DeclarationReference: Parser does not handle certain inputs correctly

@rbuckton I’m using this issue to track some bugs found while testing the DeclarationReference API. They are minor enough to be fixed in the same PR.

1. The @microsoft/rush-stack-compiler-3.5 package name is not handled correctly because of the . in the name:

   // (Actual) SyntaxError: SyntaxError: Invalid Component '@microsoft/rush-stack-compiler-3.5'
   // (Expected) @microsoft/rush-stack-compiler-3.5!
   console.log(DeclarationReference.package('@microsoft/rush-stack-compiler-3.5').toString());
   
   // (Actual) @microsoft/rush-stack-compiler-3.5
   // (Expected) @microsoft/rush-stack-compiler-3.5!
   console.log(DeclarationReference.parse('@microsoft/rush-stack-compiler-3.5!').toString());
   
   // (Works correctly) @scope/package!
   console.log(DeclarationReference.parse('@scope/package!').toString());
   

2. The parser wrongly accepts an NPM package name that is missing the !. The input should really be interpreted as a package, because @ is not a valid identifier, but packages should require the ! suffix to avoid confusion:

   // (Actual) @scope/my-package
   // (Expected) SyntaxError
   console.log(DeclarationReference.parse('@scope/my-package').toString());
   
   // (Works correctly) @scope/my-package!
   console.log(DeclarationReference.parse('@scope/my-package!').toString());
   

3. The parser wrongly accepts identifiers containing spaces.

   // (Actual) a.b c.d
   // (Expected) SyntaxError
   console.log(DeclarationReference.parse('a.b c.d').toString());
   

[rbuckton]

Do you have any objection to simply scanning forwards until we find the ! delimiter and then parsing the two halves separately?

No, its probably not a problem. I took a look and should have a PR up shortly.

[octogonz]

@rbuckton I validated that issues (1) and (2) are fixed, but issue (3) still repros:

// (Actual) a.b c.d
// (Expected) SyntaxError
console.log(DeclarationReference.parse('a.b c.d').toString());

I’m going to go ahead and merge your PR, though, so we can unblock https://github.com/microsoft/web-build-tools/pull/1406. I’ll open a separate issue for this (relatively minor) edge case.