APPS-1836 Ensure immutable routine configuration in backup and restore

[korotkov-aerospike]

This PR refactors the service layer to pass *model.BackupRoutine objects instead of routine names (string) across the application (Orchestrator, Registry, Backend Service, Retention Manager).

Key Changes:

• Contextual Data Flow: Services now operate on self-contained BackupRoutine objects, reducing the need for repeated configuration lookups and locking.
• Model Update: model.BackupRoutine now includes its own Name field.
• Concurrency Safety: Added a Copy() method to BackupRoutine to provide safe, immutable snapshots of routine configurations to async processes.
• Registry Decoupling: RunningBackupsRegistry now consumes a narrower routineProvider interface instead of the entire Config object.
• Fix: Added validation in PopInvalidatedRoutines to ensure deleted routines do not cause nil pointer exceptions.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 73.11828% with 25 lines in your changes missing coverage. Please review.
✅ Project coverage is 50.57%. Comparing base (11925e0) to head (6364b67).

Files with missing lines	Patch %	Lines
pkg/service/restore_data.go	0.00%	5 Missing ⚠️
pkg/service/backup_routine_orchestrator.go	80.95%	3 Missing and 1 partial ⚠️
pkg/service/retention_manager.go	60.00%	0 Missing and 4 partials ⚠️
pkg/service/history_manager.go	0.00%	3 Missing ⚠️
pkg/service/retrieve_config.go	0.00%	3 Missing ⚠️
pkg/service/cluster_config_writer.go	0.00%	2 Missing ⚠️
pkg/service/running_backups_registry.go	89.47%	2 Missing ⚠️
pkg/dto/config.go	50.00%	0 Missing and 1 partial ⚠️
pkg/service/backup_namespace_runner.go	83.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##               v3     #468      +/-   ##
==========================================
+ Coverage   50.41%   50.57%   +0.16%     
==========================================
  Files          82       82              
  Lines        5397     5366      -31     
==========================================
- Hits         2721     2714       -7     
+ Misses       2470     2450      -20     
+ Partials      206      202       -4     

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[korotkov-aerospike]

Tests passed https://automation.ecoeng.dev/jenkins/job/abs/job/test-abs-locally/job/gcp-aws-setup/12/console