JDBC 4.5 support: review JDBC 4.5 to see if changes are needed

[mrotteveel]

Java 26 introduces JDBC 4.5; review JDBC 4.5 to identify necessary changes (https://jcp.org/aboutJava/communityprocess/maintenance/jsr221/index5.html).

Identified changes (work in progress):

• JDBC 4.5 support: update JaybirdTypeCodes.DECFLOAT to use standardized value #906
• JDBC 4.5 support: Firebird-specific implementation of various enquote methods on Connection #908
• JDBC 4.5 support: add support for selectively disabling escape / parameter marker processing (JDBC escape {\ ... \}) #909

Still to do:

• Review the javadoc-diff to see if we missed anything based on the spec-diff
• Double check Appendix B Data Type Conversion Tables changes; we should already have the necessary conversions, but verify to be sure

No impact:

• AutoCloseable on Blob/Clob/NClob: default implementation calling free() should be sufficient

[mrotteveel]

Support will be provided in Jaybird 5 and 6, but no target version set yet as we intend to target the first release after Java 26 release.

[mrotteveel]

Doing this before the Java 26 release shouldn't cause any issues, though.