This decouples Ci::Config to provide a common interface for handling
user configuration files.

Enables frozen string for the following:

* lib/gitlab/patch/**/*.rb
* lib/gitlab/popen/**/*.rb
* lib/gitlab/profiler/**/*.rb
* lib/gitlab/project_authorizations/**/*.rb
* lib/gitlab/prometheus/**/*.rb
* lib/gitlab/query_limiting/**/*.rb
* lib/gitlab/quick_actions/**/*.rb
* lib/gitlab/redis/**/*.rb
* lib/gitlab/request_profiler/**/*.rb
* lib/gitlab/search/**/*.rb
* lib/gitlab/sherlock/**/*.rb
* lib/gitlab/sidekiq_middleware/**/*.rb
* lib/gitlab/slash_commands/**/*.rb
* lib/gitlab/sql/**/*.rb
* lib/gitlab/template/**/*.rb
* lib/gitlab/testing/**/*.rb
* lib/gitlab/utils/**/*.rb
* lib/gitlab/webpack/**/*.rb

Partially addresses gitlab-org/gitlab-ce#47424.

This prevents some of the abusive behaviors, of someone putting 100000 and creating out of memory condition easily

before:

- Method `validate_retry_max` has a Cognitive Complexity of 9 (exceeds 5 allowed). Consider refactoring.
- Method `validate_retry_when` has a Cognitive Complexity of 6 (exceeds 5 allowed). Consider refactoring.

before:

- Method `validate_retry` has a Cognitive Complexity of 7 (exceeds 5 allowed). Consider refactoring.
- Method `validate_retry_max` has a Cognitive Complexity of 9 (exceeds 5 allowed). Consider refactoring.
- Method `validate_retry_when` has a Cognitive Complexity of 14 (exceeds 5 allowed). Consider refactoring.

Use Hash#each_with_object to manipulate job hashes.

Enables frozen string for the following:

* lib/gitlab/ci/*.rb
* lib/gitlab/ci/build/**/*.rb
* lib/gitlab/ci/config/**/*.rb
* lib/gitlab/ci/pipeline/**/*.rb
* lib/gitlab/ci/reports/**/*.rb

Partially addresses #47424.

This introduces a new syntax for all licenses and performance jobs:

```yaml
job:
  reports:
    performance: performance.json
    license_management: gl-license-management-report.json
```