Optional unconventional commit parsing into message/body/footer

[approximate]

Is there an existing issue or pull request for this?

• [X] I have searched the existing issues and pull requests

Feature description

Right now unconventional commits are not parsed at all: regardless of the conventional_commits value, as soon as the commit is identified as unconventional, the parsing into message, body, and footers does not happen.

However, still parsing the message might be useful in certain circumstances:

• commiter made a mistake when adding commit type (forgot, typo, etc), so this commit will never be recognized as conventional, and we can't extract its parts
• conventional_commit is set to false in the config file, but we still want to filter/process e.g. footers
• for unconventional commits, changelog will contain the entire commit message (possibly lots of lines), even if we only need the first line (commit.message) and not the rest (commit.body)

I believe that having an option to enable commit message parsing for all commits, regardless of their type, solves many such problems,

I also believe that having a relatively established format convention (footers are recognized by git, and message is separated from the body by a single blank line, which is respected by git log --oneline) makes this feature not very controversial, even when conventional commit spec is not followed by the dev team, but they want to use git-cliff for changelog generation.

Last but not least, thanks a lot for a great product, your work is very much appreciated!

Desired solution

New configuration option "parse_commit_message" with possible values "always", "never", "conventional_only" (default value, compatible with current behaviour).

Whitespace characters should be trimmed from each parsed part of the commit.

Alternatives considered

Using built-in templating filters is possible in certain cases.

Additional context

No response