Fixes #50817

Fixes #49057

Fixes #50401

Fixes #48925

For https://github.com/Microsoft/TypeScript/pull/24138

Steps:

Use for of

Use undefined

Use namespace

Extract convertSignature

Use join for parameter label

Use map for signature.parameters

Extract getActiveParmeter

Use map to create result.signatures

Fixes #49904

Workaround for #47386

#50248

Fixes #50148

* Prototype of updating paths on rename file

* Fix apply edits

* Hook up to normal rename

* Fix unit test

* Remove timeout

* Adding prompt

* Bail early if user has set 'never'

Fixes #49985

* Add unused diagnostic subtype

Fixes #15710

Adds a new `DiagnosticTag` class that provide additional information about a diagnostic. Introduce `DiagnosticTag.Unnecessary` to mark when a diagnostic is for unused / unnecessary code

The design comes from Rosyln's diagnostic object and allows us to modify how a diagnostic is rendered without changing its serverity.

Hooks up JS and TS to use this new tag. This is controlled by the `javascript.showUnused.enabled` setting which is enabled by default

- Introduce a new diagnostic severity for unused.

    However, using this approach, if a user sets `noUnusedLocals` in their `tsconfig.json`, the resulting diagnostic could only show the squiggly OR be grayed out. Using `customTags` allows us to support both graying out and showing the squiggly

- Custom JS/TS implementation using decorators

    Not themable. We want a standard experience across languages.

* - Move to proposed
- Use numeric enum

Fixes #49866

#49022

Fixes #49024
Fixes #49060

See #49024 for details on the problem. Makes code action providers take a range | selection. Always pass the selection if one is available.