[FEAT] Accent-insensitive search or optional setting for diacritic handling

Currently, KeePass search is case-insensitive, which is very helpful. However, it is not accent-insensitive (diacritic-insensitive), which can be a limitation for many languages.

In languages such as Spanish (and many others), accented characters are very common (á, é, í, ó, ú, ñ, etc.). In everyday usage, it is easy to forget accents, both when creating an entry and when searching for it later.

For example:

• If I search for cedula, I would expect entries containing cédula to appear.
• Likewise, if I search for cédula, I would expect entries containing cedula to appear.

At the moment, these searches do not match each other, which makes finding entries harder than necessary.

Proposed solutions

• Make the search accent-insensitive by default (similar to how it is already case-insensitive), or
• Add a configuration option that allows users to enable or disable accent-insensitive (diacritic-insensitive) search behavior.

This would significantly improve usability for users of languages where accents are common, without negatively impacting users who prefer the current behavior.

No file, test, or entry point is named in the issue. Start by locating the Android search implementation and its existing case-insensitive matching, then determine whether the default behavior or a user setting is intended. Done means searches for accented and unaccented forms match as described, with the chosen behavior covered by tests.