♻️ [RUM-8123] Introduce a hook to assemble events

[amortemousque]

Motivation

The overall goal is to create a Modular SDK to simplify contributions and enhance extensibility.

This PR introduces a hook system, initially used to decouple event assembly. Each collection module can now independently handle the assembly of its own properties.

Changes

• Introduce a Hooks system
• Utilize the Assemble hook in viewCollection to manage the assembly of view properties

Testing

• Local
• Staging
• Unit
• End to end

---

I have gone over the contributing documentation.

[amortemousque]

Change unrelated to the PR, but we can remove RumContext and directly use the CommonProperties type generated by the rum-event-format

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 93.75000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 93.71%. Comparing base (9fbe626) to head (1893d43).

Files with missing lines	Patch %	Lines
packages/rum-core/src/hooks.ts	87.50%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3289      +/-   ##
==========================================
+ Coverage   93.68%   93.71%   +0.02%     
==========================================
  Files         288      289       +1     
  Lines        7617     7633      +16     
  Branches     1739     1740       +1     
==========================================
+ Hits         7136     7153      +17     
+ Misses        481      480       -1     

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[cit-pr-commenter]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	145.66 KiB	145.93 KiB	280 B	+0.19%	✅
Logs	51.09 KiB	51.09 KiB	0 B	0.00%	✅
Rum Slim	104.45 KiB	104.71 KiB	258 B	+0.24%	✅
Worker	24.50 KiB	24.50 KiB	0 B	0.00%	✅

🚀 CPU Performance

Action Name	Base Average Cpu Time (ms)	Local Average Cpu Time (ms)	𝚫
addglobalcontext	0.002	0.002	0.000
addaction	0.035	0.040	0.005
addtiming	0.001	0.001	0.000
adderror	0.044	0.053	0.009
startstopsessionreplayrecording	0.007	0.011	0.004
startview	0.462	0.491	0.029
logmessage	0.020	0.020	0.000

🧠 Memory Performance

Action Name	Base Consumption Memory (bytes)	Local Consumption Memory (bytes)	𝚫 (bytes)
addglobalcontext	27.57 KiB	27.40 KiB	-172 B
addaction	56.55 KiB	55.80 KiB	-762 B
addtiming	25.51 KiB	25.00 KiB	-530 B
adderror	59.36 KiB	58.38 KiB	-998 B
startstopsessionreplayrecording	26.77 KiB	25.28 KiB	-1522 B
startview	416.06 KiB	419.60 KiB	3.54 KiB
logmessage	63.47 KiB	60.83 KiB	-2704 B

🔗 RealWorld