Revert "erp5_full_text_mroonga_catalog: remove erroneous Keyword Search Keys"

as discussed, it's not the right one, let's reverts commit 3f62807a.

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