erp5_full_text_mroonga_catalog: remove erroneous Keyword Search Keys

While investigating MariaDB slowdown, I noticed that some Keyword Search Keys,
ie. keys triggering search by `LIKE` instead of strict equality, were
incorrect. This seems to come from a change that happened upstream. In any
case, they can safely be removed already.

bt5/erp5_full_text_mroonga_catalog/CatalogSearchKeyTemplateItem/search_key_list.xml

-<key_list>
- <key>SearchableText | MroongaBooleanFullTextKey</key>
- <key>catalog_full_text.description | MroongaBooleanFullTextKey</key>
- <key>catalog_full_text.title | MroongaBooleanFullTextKey</key>
- <key>full_text.SearchableText | MroongaBooleanFullTextKey</key>
-</key_list>
\ No newline at end of file

bt5/erp5_full_text_mroonga_catalog/bt/template_catalog_search_key_list

-SearchableText | MroongaBooleanFullTextKey
-catalog_full_text.description | MroongaBooleanFullTextKey
-catalog_full_text.title | MroongaBooleanFullTextKey
-full_text.SearchableText | MroongaBooleanFullTextKey
\ No newline at end of file