* Remove RuntimeIdentifier specification

* Arcade directory layout

This is still needed for running unit tests, but just in one place. We
can remove it everywhere else.

Right now VB doesn't have the concept of "default namespace". But we conjure one in workspace by assigning the value of the project's root namespace to it. So various feature can choose to use it for their own purpose. In the future, we might consider officially exposing "default namespace" for VB project (e.g. through a <defaultnamespace> msbuild property)

This was a policy we previously had in place, but I accidentally deleted
the tests covering it in 2d86a7b6.

The problem was our CPSProject type no longer was implementing the ENC
interfaces the project system expects; this copy/pastes the same code
over that's being used for AbstractLegacyProject.

If we don't do this, projects will end up with dangling project
references, which isn't something we want. Even if the project later
reloads, the fact there's still old ProjectIds floating around causes
us to fail to convert to P2P references again later.

Fixes https://devdiv.visualstudio.com/DevDiv/_workitems/edit/714766.

- Reverted FormatCommandHandler.FormatDocument
- Removed option search configuration for code cleanup

We initialize AssemblyName when we create the project with the
project system name (because the workspace requires we have something).
But ocne we get the real path, we need to use the real name.

Our explicit layout was not correct on 64-bit, which we do run these
tests on.

We had separate tests for P2P conversion for both legacy shims and
through the CPS APIs. Now tha the code is identical, we'll keep just
the CPS ones.

If creating three projects with three individual asserts, we should
just have three tests.

There are a number of TODOs in this commit that will need to be worked
out.

Noticed that we never did this in Roslyn correctly: the fix is simple.

This produces a new free-threaded, well factored API for adding projects
to the VisualStudioWorkspace. The core type is the VisualStudioProject
which is a free-threaded API that you can use to push information over.
CSharpProjectShim, VisualBasicProject and CPSProject each have an
instance of VisualStudioProject that they push things through.

The inheritence model here is now smaller. CSharpProjectShim and
VisualBasicProject inherit from AbstractLegacyProject, but that's it.
CPSProject now inherits nothing, and AbstractProject is here purely
for TypeScript back-compat until they're moved onto the new APIs. The
expectation is F# and TypeScript both move to VisualStudioProject, which
we make public in some form. Then that type will go away.

This ports https://github.com/dotnet/roslyn/pull/28472, that went into the `editorconfig-ide` feature branch, into `dev16.0.x` branch with following additional refactorings/enhancements:

1. Generated .editorconfig file has all localized string as comments.
2. No hardcoding of individual options in the editorconfig file generator. Instead, each `EditorConfigStorageLocation` now requires to provide a delegate to convert a given option value into the .editorconfig string representation (basically complimentary of the parsing delegate that was already required).
3. Introduce concept of `OptionGroup` to enable grouping options in the same feature (such as CodeStyleOptions, CSharpCodeStyleOptions, FormattingOptions, CSharpFormattingOptions, etc.) into sub-features or groups (such as "this. preferences", "expression-level preferences", etc.). This enables the editorconfig generation to group the related options, without explicit knowledge of each option group.
4. Expose `AllOptions` from each option feature (such as CodeStyleOptions, CSharpCodeStyleOptions, FormattingOptions, CSharpFormattingOptions, etc.), so that the corresponding `IOptionProvider` always stays in sync with implemented options.

* Rename target GetBuildVersion to GetVsixVersion

* Targets refactoring to align with Arcade SDK

* Remove unused property

* Use Arcade VSIX build targets

* Upload Willow VSIXes directly from VSSetup directory

* Add setup packages to Roslyn.sln

* Remove swr validation from BuildBoss

* Avoid copying CoreXT packages

* Don't delete DevDivPackages\Roslyn dir

* Upload vsixes even when the build fails

* Clean up VSIX project files

* Install VSIXes in specified order

* Do not set TargetFrameworkVersion.

* Fix parameter

* DevDivInsertion better error message

* Remove 'win' from target string

* Fix dir name

* Install Setup.Dependencies

* Default values for insertion components

* Make BuildBoss happy

* Fix VSIX path

* NGEN binaries that should have been NGEN'd

* RoboCopy returns non-zero exit code on success

* Pass OfficialBuild property to vsmanproj

1. Break the analyzer into two separate diagnostics for flagging unused and unread members. Latter rule has no code fix.
2. Remove all UI option elements for the added diagnostics and turn the rules off by default for now.
3. Bail out for invalid operations and syntax errors.
4. Handle doc comments and nameof - report unread member diagostics instead of unused member diagnostics if referenced in non-read/write context.

* NuGet packaging

* Add missing VS package references

* Fix scripts

* Add comment on Workspace.Desktop references with PrivateAssets

* Fix Microsoft.NETCore.Compilers package

* Fix up references

* Build fixes

* Correct OutputPath for package projects

* Use NuGetRepack to force exact versions in per-build packages