♻️ [RUMF-1436] instrument method improvements

[BenoitZugmeyer]

Motivation

In the process of fixing RUM-211 (some methods are "readonly" and their instrumentation breaks the SDK), I wanted to use the functions to instrument methods in more places. This PR is a step in that direction: it revamps and factorizes our existing intrument methods functions into a single, more easily extendable one.

Changes

This PR changes the instrumentMethodAndCallOriginal signature to call the intrumentation callback with a InstrumentedMethodCall object containing the target and parameters properties instead of passing them directly as this and function arguments.

This new InstrumentedMethodCall object also allows to:

• register a "post call" callback that will be called with the original method result
• mutate the parameters in-place

This allows to use instrumentMethodAndCallOriginal in fetchObservable. By doing so, the original instrumentMethod function isn't used anymore, and we can keep a single function for all our method instrumentations.

This new InstrumentedMethodCall object will also allow to transmit more information in the future, like the "handling stack" to allow using our instrumentation tooling for console.* methods.

Testing

• Local
• Staging
• Unit
• End to end

---

I have gone over the contributing documentation.

[codecov-commenter]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (49dba56) 92.83% compared to head (0ac913f) 92.82%.
Report is 1 commits behind head on main.

Files	Patch %	Lines
...s/rum-core/src/browser/locationChangeObservable.ts	75.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2551      +/-   ##
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- Coverage   92.83%   92.82%   -0.01%     
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  Files         227      227              
  Lines        6714     6706       -8     
  Branches     1480     1478       -2     
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- Hits         6233     6225       -8     
  Misses        481      481              

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