Improve HM type inference diagnostic messages

[bamarsha]

• Fix incorrect diagnostic ranges caused by StripPositionInfoFromType not stripping ranges from TypeRange.
• Improve phrasing and give more information in type mismatch, missing base type, and ambiguous type parameter diagnostics:
  • For ambiguous type parameter diagnostics, show the constraints applied to the type parameter.
  • Call attention to type mismatches with explicitly bound type parameters (i.e., an alternative to the original "constrains type parameter" error).
• Add test cases for issues Type Argument Inference Fails if the same Type Parametrized Callable is used Multiple Times #573 and Some non-concretized callables are allowed to be called or given as arguments #662 that are fixed by HM.

Note: @cesarzc reported an issue where multi-line diagnostic messages were cut off after the first line in Visual Studio, but I can't reproduce the issue. Here is what they look like for me:

[swernli]

Looks good to me!