[RUMF-1147] 🐛 Implement TextEncoder().encode fallback for replay encorder

[amortemousque]

Motivation

RUM session replay on Edge 18 when encoding records to UTF-8 an error is thrown.
This PR implement a fallback if TextEncoder().encode is not supported.

Changes

• Fallback with pakostring2buf encoding function: https://github.com/nodeca/pako/blob/master/lib/utils/strings.js#L26

Testing

• Local
• Staging
• Unit
• End to end

---

I have gone over the contributing documentation.

[amortemousque]

Talking with @BenoitZugmeyer, I tried two different approaches for the fallback:

1. using FileReader:
   It introduce an asynchronous behaviour inside the web worker and messages aren't guaranteed to be treated in order.

2. using pako encoding function
   It is synchronous but use a custom encoding function adding a bit more code

IMO, In term of complexity Pako fallback is the best solution.

Additional question:
By looking at this test I'm wondering , if it is possible to enable session replay on IE 11 or is there other blockers?

[codecov-commenter]

Codecov Report

Merging #1269 (007528e) into main (c36718f) will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1269      +/-   ##
==========================================
- Coverage   89.93%   89.90%   -0.03%     
==========================================
  Files         105      105              
  Lines        4370     4370              
  Branches      989      989              
==========================================
- Hits         3930     3929       -1     
- Misses        440      441       +1     

Impacted Files	Coverage Δ
packages/core/src/tools/timeUtils.ts	97.14% <0.00%> (-2.86%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c36718f...007528e. Read the comment docs.