Specific diagnostic suggestions for unexpected keyword or identifier (#43005)

Error message improvement for unexpected tokens in the following situations:

* A word was parsed that seems to have a low edit distance from a known common keyword
* A word was parsed that seems to be a known common keyword and a name _without_ a space in-between
* Parsing in a particular type of node (mostly a class property declaration) got a different word or token than expected

___

* Specific diagnostic suggestions for unexpected keywords or identifier

* Don't reach into there, that's not allowed

* Improved error when there is already an initializer

* Specific module error message for invalid template literal strings

* Skip 'unexpected keyword or identifier' diagnostics for declare nodes

* Improve error for function calls in type positions

* Switch class properties to old diagnostic

* Corrected errors in class members and reused existing textToKeywordObj map

* Corrected more baselines from the merge

* Update src/compiler/parser.ts

Co-authored-by: Daniel Rosenwasser <DanielRosenwasser@users.noreply.github.com>

* Mostly addressed feedback

* Clarified function call type message

* Split up and clarified parsing vs error functions

* Swap interface name complaints back, and skip new errors on unknown (invalid) tokens

* Used tokenToString, not a raw semicolon

* Inline getExpressionText helper

* Remove remarks in src/compiler/parser.ts

Co-authored-by: Daniel Rosenwasser <DanielRosenwasser@users.noreply.github.com>

src/compiler/scanner.ts

@@ -77,7 +77,8 @@ namespace ts {
         tryScan<T>(callback: () => T): T;
     }
 
-    const textToKeywordObj: MapLike<KeywordSyntaxKind> = {
+    /** @internal */
+    export const textToKeywordObj: MapLike<KeywordSyntaxKind> = {
         abstract: SyntaxKind.AbstractKeyword,
         any: SyntaxKind.AnyKeyword,
         as: SyntaxKind.AsKeyword,