HSQL to Firebird auto migration firebird data types

Hi,

Looking at the open issues for the HSQL to Firebird auto migration
functionality particular the issues regarding data types and other test
files I put together a possible map of what I think makes sense in
translating hsql to firebird types.  [Read only view of it here
https://nextcloud.documentfoundation.org/s/TTBT4fJ2xTdbMJQ ]

I'm sharing it here for two purposes, first it would be a big help to have
this type of thing with whatever the actual mapping is - so - if that is
already set I could really use for someone to let me know what would need
to change there.

However; Secondarily and since it doesn't seem to be settled in the code at
the moment I wand to propose this mapping.

The are three suggested changes;
first is to treat OTHER[OTHER] as a custom subt_type (-1) of blob instead
of a CLOB as this would give the same behavior in Base with firebird as
with hsql

second is to treat HSQL Binary(fix)[BINARY] as Binary[BINARY]  with
sub_type of 0 or 1 based on a scan of some number of the records checking
for text data

And the third would be to display two additional labels in table editor
(Memo[Blob] and OTHER[BLOB]) for consistency with the current UI using hsql.

Either way it's good see the work going on and I'm excited to help as I can.

Best wishes,
Drew