Problem: Attempting to create a foreign key matching a SPATIAL index
would lead to an assert in debug mode. Creating a foreign key matching
a FULLTEXT index would fail.

Root cause was that the keys generated by the server for the foreign
keys in this case were ignored since the generated key was considered
a prefix of the SPATIAL or FULLTEXT key.

Solution: Exclude SPATIAL and FULLTEXT keys from the set of keys that
can be used in place of the generated key when the latter is a
prefix. Note that it isn't (and never was) possible to create a
foreign key on a GEOMETRY column, so the fix causes the same error to
be reported even if there happens to be a SPATIAL index on the column.

Some negative tests fail with different error messages with this
change and have to be updated.

(cherry picked from commit 81089203a91e6fb17105422684a4ccdb08a7b3d9)