Improve parameter type matching regex

[seraku24]

Fixes (again) #657 as well as issues brought up in #670.

• Corrects the order of type, template arguments, nullable type specification and array specifications.
• Ensures array specification support all forms (simple arrays, multi-dimensional arrays, arrays of arrays).

[seraku24]

And for comparison, here are the results of the regex on a pathological test case:

Current behavior

Updated behavior

[ivanz]

@seraku24 You may want to update the regex to handle unsafe pointers (byte* ,etc) too since you are at it. Relates to those two issues: #101 and microsoft/vscode#1093

[ivanz]

@seraku24 Also one more thing is to handle @ too e.g. string @class

[ivanz]

@seraku24 Final thing - might be worth checking if your regex also fixes the method return value highlighting problem here: #33

[seraku24]

Okay, @ivanz. I have adjusted the regex to support unsafe pointers as well as reserved keyword escaping:

Regarding return types, it seems that some types are highlighting correctly already but there are others that are not:

That said, we might want to keep the scope of this PR to just addressing the issues with highlighting parameters, which I believe we have done.

[ivanz]

Looks good to me, but @DustinCampbell is the one with the review and merge powers and I believe he is based in the US, so it's just about morning there. Congrats on your first GitHub pull request 🎉

[seraku24]

Well, compared to other source/version control systems, git and GitHub have probably been the easiest to work with, especially when compared to Product Studio or TFS. (:

Thanks for the help and encouragement. I am just glad to be able to offer some of my regex experience at the very least.

[DustinCampbell]

LGTM