FE: Create pipeline rule component

Why are we doing this work

• Users want to use a Rule mode to create a scan execution policy because yaml can be hard to parse

Relevant links

Non-functional requirements

• Feature flag:
• Testing:

Implementation plan

• frontend create pipeline rule mode on both the project and group levels (for more context, read the pipeline schema docs)
  • look at scan_result_policy_editor.vue for examples on using the policy_editor_layout.vue rule slot and do something similar in scan_execution_policy_editor.vue by creating a scan execution policy_rule_builder.vue component
  • look at the files in the scan_result_policy/lib directory on how to convert to/from yaml (e.g. to_yaml.js, from_yaml.js, humanize.js, and rules.js) and follow that pattern in the scan_execution_policy/lib directory
  • rule dropdown
    • there are two options for rules:
      1. A pipeline is run (handled by this issue)
      2. Schedule (handled by FE: Create schedule branch rule component (#359886 - closed))
    • for this issue, only focus on 1, but feel free to make it a drop down
  • branches dropdown
    • per &5363 (comment 894764465), give the user an input box instead for the user to type comma-delimited branches
• frontend ensure the policy_drawer continues to display the humanized policy correctly

Verification steps

1. Upload a GitLab Ultimate license
2. Turn on the :scan_execution_rule_mode feature flag
3. Navigate to a project => Security & Compliance => Policies => New policy => Scan Execution Policy
4. Verify rule mode branches rule works
5. Navigate to a group => Security & Compliance => Policies => New policy => Scan Execution Policy
6. Verify rule mode branches rule works