Bug 21294: Replace BOOLEAN with TINYINT(1) in our DB structure

Bug 21294: Replace BOOLEAN with TINYINT(1) in our DB structure

To match the coding guideline SQL12.
We do this for consistency.
Note that we do not need an update DB as BOOLEAN is an alias for
TINYINT(1).

The is_boolean flags have been added to the schema.

Test plan:
1. `dbic` should run correctly
2. kohastructure.sql should be syntaxicaly correct
3. `git grep -i boolean installer/data/mysql/kohastructure.sql`
should not return relevant occurrences.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>