Incorrect variable declaration lookup within function

[genius257]

Variable lookup within a function does not work as expected.

          @genius257 Unfortunately, the latest update appears to have broken the GTD functionality for functions. ☹️

Originally posted by @Danp2 in https://github.com/genius257/vscode-autoit/issues/24#issuecomment-1483173951

Example:

#include <Array.au3>

$x = 123

Func x()
    $x = 321
    $MB_HELP
    $x
EndFunc

The issue with the $MB_HELP declaration is caused partially by the parser: https://github.com/genius257/autoit3-pegjs/issues/33#issue-1640268416

The remaining declaration resolve problem is caused by the Local/Global/Auto scope of a variable not being taken into account, within a function.

As matching variable declarations are found within the function (before the lookup origin), the scope of the declaration must be updated.

• Global will do nothing special, and let the general global lookup logic handle declaration mach finding.
• Local will override previous global scope declarations and cannot be scope overridden. Meaning first matching declaration with local scope will be a match.
• Auto will keep first matching declaration as a fallback if the general global lookup returns nothing.

[genius257]

The behavior of goto declaration feature within a function scope is tricky. Global matching still is not perfect, and I am unsure if the current implementation is correct. I will mark this as completed for now, expecting an issue specificlly for global variable lookup behavior can be discussed, at a later date if need be.