[rom_ext] Setting minimum required BL0 security version should not honor bad request

### Description

If the currently active owner firmware image requests a minimum security version that is higher than its current security version, the request to ROM_EXT should be ignored (or return and error). Otherwise, an image could lock itself out of running on the chip.

See also #19585

Trace how ROM_EXT handles the active owner firmware image's requested minimum BL0 security version, then review the related discussion in issue #19585. Done means a request above the image's current security version cannot lock the image out: it is ignored or returns an error, with behavior verified by relevant regression coverage.

Written by the indexing model from the issue text.