Replace Legacy JetStream API and Update updateStream Function

[kianaza]

• Replace legacy JetStream API with the new JetStream API.

• Update the updateStream function to prevent configuration changes during stream updates.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 74 lines in your changes missing coverage. Please review.

Project coverage is 0.00%. Comparing base (3f7b729) to head (2b39ef8).
Report is 60 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/natsclient/jetstream.go	0.00%	70 Missing ⚠️
internal/cmd/main.go	0.00%	3 Missing ⚠️
internal/config/default.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff          @@
##            main     #10   +/-   ##
=====================================
  Coverage   0.00%   0.00%           
=====================================
  Files          9       9           
  Lines        296     308   +12     
=====================================
- Misses       296     308   +12     

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