Remove some API from haxe.macro.Compiler

[Simn]

Reasons follow:

removeField and setFieldType

I don't know what this was used for, but I'd like to think that we've moved beyond doing string-based patching operations like that.

addMetadata

This has always had some sort of issues that I don't remember right now, but it was replaced by addGlobalMetadata for a reason. In fact, I've changed it here to use that, in a way that makes sense to me. The only difference should be that isStatic is now ignored.

patchTypes

To my knowledge, this is ancient legacy from making flash externs. I don't think anyone even remembers the format this uses.

includeFile

According to my investigations and #6252, the position argument never worked properly. The lua generator only checked for "top", which means that "closure" would silently be ignored. Genjs does check both, so there's a chance that somebody was actually using the latter somehow and we're breaking this now. That's a risk I'm willing to take. I can't see how "inline" ever did anything because it only makes sense from a macro call, and that's the part that never worked in the first place.

Edit: One thing that maybe worked was using "inline" directly instead of IncludePosition.Inline... So I guess maybe this was used after all. I'll still try to remove it because I'd like to discourage putting js.Syntax.plainCode things in code.

Edit: Never mind, too controversial.

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Will leave this open for a bit and see if somebody complains too loudly.

[Simn]

Ok I lied, when I said I'd leave this open I was mostly concerned about the includeFile changes. I definitely want to remove the patchTypes parts, so I'll go ahead and merge this!