Allow queries also for HSQLDB databases

If you install Admin Tools, on the homepage, the database tools are not displayed, mentioning that they are intended only for MySQL database, see message.png

The Admin.Query page is working for HSQLDB with the appropriate parameter values. We should:

• provide a select in the Admin.Query page for HSQLDB and MySQL, prefilling the parameters values;
• remove the info message restricting the page only for MySQL.

Parameters for:

• HSQLDB

  user: sa
  password:
  URL: jdbc:hsqldb:file:data/database/xwiki_db;shutdown=true
  driver: org.hsqldb.jdbcDriver
  

• MySQL

  user: xwiki
  password: xwiki 
  URL: jdbc:mysql://localhost/xwiki?useServerPrepStmts=false&useUnicode=true&characterEncoding=UTF-8
  driver: com.mysql.jdbc.Driver