Parsing stack (#5277)

[Moderocky]

Re-opening the abandoned #5277 with updated changes.

Description

This PR adds the parsing stack. This is a stack that keeps track of which syntax elements are currently being parsed.
With this feature, you could for example check in an expression's init method which expression it's being used in, or which effect is using the expression.

Each stack element contains the SyntaxElementInfo (which contains info such as the syntax element class and the patterns), and which exact pattern was used.

This PR also catches StackOverflowErrors that occur during parsing, and adds the parsing stack to the exception message. AFAIK these exceptions are rare here, but the extra details don't hurt. Example stack trace (warning: long): https://pastebin.com/CNynV19h

I also plan to add a watchdog system where Skript would detect when parsing is taking a long time (either in general, or for a specific line / trigger), at which point Skript could print some warning message, including the parsing stack and possibly more information, to console.

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Target Minecraft Versions: any
Requirements: none
Related Issues: none