[release/7.0][wasm][debugger] Improvements in debugging in async methods

[thaystg]

Backport of #78651 to release/7.0

/cc @thaystg

Customer Impact

When a async method has 2 variables with same name in different scopes, the debugger was always getting the value from the last scope, so if it was debugging and paused in a if block, that has an else with the same variable in two blocks, it would show the wrong value for the variable in debugger.
Fixed this for C# and VB, also fixed names of async variables and methods while debugging VB code.
Issues related:
#77031
#77481
https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1697672

Testing

Manually tested using a Blazor app, also created unit tests.

Risk

Medium risk, now it's considering the scope of variables in async method, this was completely ignored before.

[ghost]

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Issue Details

---

Backport of #78651 to release/7.0

/cc @thaystg

Customer Impact

When a async method has 2 variables with same name in different scopes, the debugger was always getting the value from the last scope, so if it was debugging and paused in a if block, that has an else with the same variable in two blocks, it would should the wrong value for the variable in debugger.
Fixed this for C# and VB, also fixed names of async variables and methods while debugging VB code.
Issues related:
#77031
#77481
https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1697672

Testing

Manually tested using a Blazor app, also created unit tests.

Risk

Medium risk, now it's considering the scope of variables in async method, this was completely ignored before.

Author:	thaystg
Assignees:	thaystg
Labels:	area-Debugger-mono
Milestone:	-

[carlossanlop]

@thaystg when this is ready, please add the servicing-consider label, then send email to Tactics requesting approval.

[thaystg]

I have already sent the email, and it's already approved :)

[carlossanlop]

Approved by Tactics (7.0.3).
Signed off by area owner.
No OOB changes needed.
CI failure in dev-innerloop looks unrelated.
Ready to merge.