Syntax highlighting for functions, variables and numbers

[Morcifer]

Supports syntax highlighting for:

• function definitions
• function calls
• numbers
• variables

See issue #1950.

The change for function calls also applies to operation definitions and to attributes (see bigger example below).
The change for variables also applies to attributes and to imports.

I might be nice to make attributes and imports get their own designated rules. I can do them as part of this PR, but I think it might be best to do as a followup issue - because I believe this PR is actually already an improvement for them.

Simple example for the change (from the original issue description):

And a bigger example:

[Morcifer]

I have sole ownership of intellectual property rights to my Submissions and I am not making Submissions in the course of work for my employer.

@microsoft-github-policy-service agree

[swernli]

Thanks for the contribution, @Morcifer! One idea I had after looking at your screenshots: would it be possible to use the presence of the @ symbol to avoid highlighting attributes like @Config() and @EntryPoint() as if they were function calls?

[Morcifer]

would it be possible to use the presence of the @ symbol to avoid highlighting attributes like @Config() and @EntryPoint() as if they were function calls?

It's definitely possible (see latest commit):

Though it still treats the attributes inside the parentheses of the Config as variables... I think it might be simpler and probably more future-proof to just make a Config-specific rule, rather than to figure out how to disable that one.

[swernli]

I think the items inside the parens of @Config look fine in the screenshot you posted. This is indeed a nice improvement!

[minestarks]

Great improvement, thank you!