fix: wrong usage of smallmap cause server crash. switched to indexmap

[giangndm]

Description

SmallMap only works with u8 compatible key, this cause some wrong in behavior. This is root issue of server crash because metadata cluster wrong in remove endpoint.

This PR switch all of SmallMap and most of HashMap into IndexMap, which is more fit for media-server where we iterate a lot.

Related Issue

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Checklist

• I have tested the changes locally.
• I have reviewed the code changes.
• I have updated the documentation, if necessary.
• I have added appropriate tests, if applicable.

Screenshots

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Additional Notes

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[codecov]

Codecov Report

Attention: Patch coverage is 84.40367% with 17 lines in your changes missing coverage. Please review.

Project coverage is 36.30%. Comparing base (707d96e) to head (c86899d).
Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
packages/transport_webrtc/src/shared_port.rs	0.00%	8 Missing ⚠️
packages/media_utils/src/indexmap_2d.rs	20.00%	4 Missing ⚠️
...ackages/media_core/src/cluster/room/audio_mixer.rs	71.42%	2 Missing ⚠️
.../src/endpoint/internal/bitrate_allocator/egress.rs	66.66%	1 Missing ⚠️
...src/endpoint/internal/bitrate_allocator/ingress.rs	50.00%	1 Missing ⚠️
packages/transport_webrtc/src/transport.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #457      +/-   ##
==========================================
+ Coverage   36.22%   36.30%   +0.08%     
==========================================
  Files         177      177              
  Lines       18031    18070      +39     
==========================================
+ Hits         6531     6561      +30     
- Misses      11500    11509       +9     

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