GEOT-7672:ElasticSearch date converter:Fixing day of month support

[dromagnoli]

Checklist

• [x] I have read the contribution guidelines.
• [x] I have sent a Contribution Licence Agreement (not required for small changes, e.g., fixing typos in documentation).
• [x] First PR targets the main branch (backports managed later; ignore for branch specific issues).
• [x] Avoid Java 9+ split packages.
• [x] All the build checks are green (see automated QA checks).

For core and extension modules:

• [x] New unit tests have been added covering the changes.
• [ ] Documentation has been updated (if change is visible to end users).
• [x] There is an issue in GeoTools Jira (except for changes not visible to end users).
• [x] Commit message(s) must be in the form [GEOT-XYZW] Title of the Jira ticket.
• [x] Bug fixes and small new features are presented as a single commit.
• [x] The commit targets a single objective (if multiple focuses cannot be avoided, each one is in its own commit, and has a separate ticket describing it).