Change implementation of a SynthesizedRecordConstructor to act more like a constructor declared in source. (#44803)

* Change implementation of a SynthesizedRecordConstructor to act more like a constructor declared in source.

In addition:
- Fixes #44781.
- Fixes #44782.

Related to #41704.

Closes #28834.
Closes #30061.

 Adjust base access with explicit base according to latest LDM decisions

- Restrict accessed members to immediate members of the specified type.
- Change accessibility of explicit implementations in interfaces to ‘protected’.

e.g. `ReturnType`, `ElementType`, etc.

- Rename `TypeSymbolWithAnnotations` to `TypeWithAnnotations`
- Rename its type field from `TypeSymbol` to `Type`
- Fields of Symbols that are of type `TypeWithAnnotations` that are currently named `Type` would be renamed `TypeWithAnnotations`
Fixes #33736

Closes #30171.
Closes #29838.

Use synthesized attribute infrastructure for System.NullableAttribute

* IDE Changes

* tests

* PR comments

* Remove context (enclosing type name) from C# parser.
* Add a test demonstrating that unicode escapes are significant to determining if a method is a ctor.
This is a prerequisite to #367

LocalFunctionTypeParameterSymbol isn't necessary as long as the functionality around type constraints can be moved into a shared base class between ordinary method symbols and local function symbols.
In fact, it would be very useful to have a shared base symbol aside from MethodSymbol between local functions, lambdas, and other source method symbols. To this end, I've renamed SourceMemberMethodSymbol to SourceOrdinaryMethodSymbol (since it is just used for ordinary member-level methods), SourceMethodSymbol to SourceMemberMethodSymbol (since it is only used as a base class for member-level method-like functions like ordinary methods, constructors, property accessors, et al.), and added a new abstract class SourceMethodSymbol that is the root of both LocalFunctionSymbol and SourceMemberMethodSymbol. This lets us unify all source method-like symbols under a single base class, SourceMethodSymbol.
The first three commits perform the refactoring, while the last commit actually removes LocalFunctionTypeParameterSymbol and moves the necessary functionality into SourceMethodSymbol. I expect more functionality to be moved over in subsequent PRs.

Fixes #17244

Fixes #19950

* Call this.DeclaringCompilation.EnsureReadOnlyAttributeExists() when needed

* Promote EmbeddedAttribute to be used by both compilers

* Generate Embedded attributes on PE Module Builder

* Thread PEModuleBuilder through Symbol.AddSynthesizedAttributes()

* Fix failing tests

* Base case passing

* Refactor ReadOnlyAttribute to IsReadOnlyAttribute

* Fix build break

* More Tests

* Clean up

* PR Comments #1

PR Comments #3

PR Comments #4

PR Comments #5

PR Comments #6

PR Comments # 7

* Handle NoPIA

Added more tests

* Lambdas and Local functions no longer generate attributes in symbols

Added tests for constructors and operators

Signal need for synthesized attributes in local rewriter for lambdas an local functions

Clean up

* Clean up

* More PR Feedback

* Adding more tests

* More PR Comments

* More tests for explicit interface implementations

* Latest PR Comments

* Moved EnsureIsReadOnlyAttributeExists to AfterAddingTypeMembersChecks

* Fix failing tests

Make local function default parameter value binding lazy

Current strict binding can cause circularity problems when local
functions are referenced. This change causes local functions to use lazy
default parameter binding, similar to methods, and then forces their
construction when diagnostics are requested for the local function.

This also requires a mechanism for recording declaration diagnostics
outside of adding to the compilation's DeclarationDiagnostics. A new
type, DeclarationDiagnosticStore is introduced as an abstraction to
store declaration diagnostics on either the compilation or in a local
DiagnosticBag, depending on the needs of the symbol storing diagnostics.

Fixes #16451, #17293

* Move more errors out of the parser.

* PR feedback.

* Move to a single diagnostic.

* Add period.

* Update text.

* Update tests.

* Fix test.