Add Spring MVC scaffolding provider

[ivannov]

After installing this addon and calling the scaffold-setup command, the latter should offer spring mvc as scaffold provider. For each entity it should generate an MVC controller and inject a repository in it. As a beginning only JSP will be supported as view technology, so the command will finally generate view and edit JSPs for each entity. If for a certain entity there is no repository, the command should generate it as well (reusing the code that is used by the add repository command).

This command should be only available if spring boot jpa facet is installed.

[gochev]

What is done:

• dedicated provider which can be invoked
• it checks is the SpringBootFacet installed we need to check for Spring JPA facet there as well ones its done
• it generates 3 classes per entity 2 jsps and 1 controller

What has to be done:

• the wizard (currently faces wizard)
• the pre-invocation of generate repositories command if this command is not invoked.
  • Open Question : are we generate repositories in fixed package and can we depend on it ? like basePackage.repository, otherwise it will be hard to find where the repository is based on entity.
• Fix the FTL templates and conext map they use.. currently we do generate 3 templates for each entity. However the code in the 2 jsps and in the java are all hardcoded for "user" we need to change this user with the entityName.