Simplify EPB PolyglotProxy with ReflectionLibrary

[wdanilo]

This task is automatically imported from the old Task Issue Board and it was originally created by jaroslavtulach.
Original issue is here.

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PolyglotProxy is responsible for delegating interop messages from Enso to JavaScript, Python, R. It is a repetitive piece code fragile to copy&paste programming. It has to be updated with every GraalVM update (e.g. #182845176) as the set of interop messages changes.

ReflectiveLibrary has been recently discovered by us that could simplify the whole proxying to a single send method.

Demonstrated on WithWarnings.

Can the same approach be applied to PolyglotProxy?

[JaroslavTulach]

• the code has already been simplified by Run Enso tests with assertions enabled #7882
• The PolyglotProxy & related classes were deleted
• Instead we rely on Truffle's own proxying between TruffleContext instances of Enso and JavaScript
• we reported Let languages control multi threaded access ... is not allowed for language(s) js oracle/graal#8033 to be on par with Enso original implementation
• the fix was integrated on Sep 27, 2024: Allow control of throwDeniedThreadAccess via TruffleContext.threadAccessDeniedHandler oracle/graal#8266
• we are not yet using it - we will once we upgrade to new Truffle

In any case, we can close this issue as fixed.