refactor(prompts): streamline commit message generation logic

[cometjc]

This update introduces a new structure for generating commit messages by defining a constant for commit types and consolidating the logic into a single function. The changes enhance readability and maintainability while ensuring consistent formatting based on the OCO_OMIT_SCOPE configuration.

---

This merge request is the first of five commits intended to archive feat(commitlint): Improve consistency handling and prompt structure. I have split the changes into five reviewable merge requests that will be submitted sequentially.

---

feat(commitlint): Improve consistency handling and prompt structure

Problem:
The current commitlint integration has limitations in generating commit messages that strictly follow commitlint rules. For example, when commitlint config has body-leading-blank: [2, 'always'], the default prompt cannot generate messages with proper blank line between header and body:

- feat(scope): add new feature
- This is the body text
+ feat(scope): add new feature
+ 
+ This is the body text

Solution:
We refactor the consistency handling to use the default commit message format as a reference style, while ensuring the generated messages strictly follow commitlint rules. This approach:

1. Uses the default content as a reference for style and features
2. Generates dynamic requirements based on config settings
3. Ensures the message follows all commitlint rules
4. Maintains backward compatibility

[di-sukharev]

thank you, this is cleaner