✨ Use tree walker for action name computation

[cy-moi]

Motivation

We have tested tree walker approach and the previous approach of action name computation back to back, it seems that the risk of switching to tree walker is low (results are identical on staging). The tree walker approach is more secure and efficient. It also gives alignment between action name and SR rendered texts.

Changes

Remove feature flag of using treewalker
Remove legacy action name compuation approach
Fix test cases by removing the FF mock

Test instructions

Should pass CI

Checklist

• Tested locally
• Tested on staging
• Added unit tests for this change.
• Added e2e/integration tests for this change.

[cit-pr-commenter]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	164.05 KiB	163.64 KiB	-424 B	-0.25%	✅
Rum Profiler	4.84 KiB	4.84 KiB	0 B	0.00%	✅
Rum Recorder	19.50 KiB	19.50 KiB	0 B	0.00%	✅
Logs	55.91 KiB	55.84 KiB	-68 B	-0.12%	✅
Flagging	944 B	944 B	0 B	0.00%	✅
Rum Slim	121.33 KiB	120.92 KiB	-416 B	-0.33%	✅
Worker	23.63 KiB	23.63 KiB	0 B	0.00%	✅

🚀 CPU Performance

Action Name	Base CPU Time (ms)	Local CPU Time (ms)	𝚫%
RUM - add global context	0.0048	0.0054	+12.50%
RUM - add action	0.0116	0.0148	+27.59%
RUM - add error	0.0115	0.0173	+50.43%
RUM - add timing	0.0025	0.0031	+24.00%
RUM - start view	0.0032	0.0039	+21.87%
RUM - start/stop session replay recording	0.0007	0.0009	+28.57%
Logs - log message	0.0126	0.0215	+70.63%

🧠 Memory Performance

Action Name	Base Memory Consumption	Local Memory Consumption	𝚫
RUM - add global context	25.95 KiB	30.17 KiB	+4.22 KiB
RUM - add action	94.27 KiB	104.48 KiB	+10.21 KiB
RUM - add timing	23.84 KiB	30.58 KiB	+6.74 KiB
RUM - add error	94.39 KiB	92.17 KiB	-2.23 KiB
RUM - start/stop session replay recording	23.32 KiB	29.21 KiB	+5.89 KiB
RUM - start view	438.71 KiB	451.01 KiB	+12.30 KiB
Logs - log message	44.03 KiB	47.80 KiB	+3.77 KiB

🔗 RealWorld