Add flag for specifying configuration file path and include cluster name in metric labels

[kianaza]

This merge request introduces functionality to enhance our application in two key ways:

1. Configuration File Path Flag:
   Added a -settings flag to allow users to specify the path to the configuration file (config.yaml).

2. Cluster Name in Metric Labels:
   Included the cluster name as part of the metric labels.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 27 lines in your changes missing coverage. Please review.

Project coverage is 0.00%. Comparing base (276bb3a) to head (cf90ea4).

Files	Patch %	Lines
internal/natsclient/jetstream.go	0.00%	14 Missing ⚠️
internal/natsclient/metric.go	0.00%	7 Missing ⚠️
internal/cmd/root.go	0.00%	3 Missing ⚠️
internal/config/config.go	0.00%	3 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff          @@
##            main      #8   +/-   ##
=====================================
  Coverage   0.00%   0.00%           
=====================================
  Files          9       9           
  Lines        279     287    +8     
=====================================
- Misses       279     287    +8     

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