starrocks [Enhancement] str_to_date supports incomplete format types in FE

Why I'm doing:

If the where condition contains a partition condition that is compared with the str_to_date function, a full table scan will be required, and FE is required to implement the str_to_date function to perform partition pruning when generating the execution plan.

What I'm doing:

implement str_to_date in FE incompletely Fixes #32625

What type of PR is this:

[ ] BugFix
[ ] Feature
[-] Enhancement
[ ] Refactor
[ ] UT
[ ] Doc
[ ] Tool

Does this PR entail a change in behavior?

[x] Yes, this PR will result in a change in behavior.
[ ] No, this PR will not result in a change in behavior.

If yes, please specify the type of change:

[ ] Interface/UI changes: syntax, type conversion, expression evaluation, display information
[ ] Parameter changes: default values, similar parameters but with different default values
[-] Policy changes: use new policy to replace old one, functionality automatically enabled
[ ] Feature removed
[ ] Miscellaneous: upgrade & downgrade compatibility, etc.

Checklist:

[-] I have added test cases for my bug fix or my new feature
[ ] This pr needs user documentation (for new or modified features or behaviors)
- [ ] I have added documentation for my new feature or new function
[ ] This is a backport pr