Stub call history should table.Copy

When storing the call history we're gonna need to be smarter about how we store the params in the case that the given arg might change after the call, especially with tables.

Even worse, ephemeral objects will just be like NULL or whatever if things change so idk exactly what to do about that.

ref: https://github.com/CFC-Servers/GLuaTest/blob/main/lua/gluatest/stubs/stub_maker.lua#L93

Start at lua/gluatest/stubs/stub_maker.lua around line 93 and trace how stub call-history arguments are stored. Determine the expected behavior for tables and ephemeral objects before choosing the smallest change. Done means later argument mutations no longer make recorded history inaccurate, with coverage for the identified cases.

Written by the indexing model from the issue text.