XD-1431 Add spring-xd-hsqldb-server project

- Create a helper project that has spring-boot, hsqldb and misc dependencies
- Move HSQLServerBean into this project
  - Create profile `hsqldbServer` and make it active for XD singlenode and standalone HSQLServer
  - Create explicit datasource with hsqldb properties to not to initiate embedded database from DataSourceAutoConfiguration
- Make this project an application
  - This will enable scripts and lib to be available following installApp gradle task and
have `copyHsqldbInstall` that will have `hsqldb` under build/dist/spring-xd
  - Set `XD_HOME` explicitly in hsqldb scripts so that the data home directory being used will have XD_HOME used
- Add this project as a dependency to `spring-xd-dirt`
  - This will enable singlenode application to use HSQLServerBean from spring-xd-hsqldb-server
  - It is expected to have the data source running prior to starting XD admin