refactor: update JHipster application generation process

[LakshitAgarwal]

attempt #29194

• Renamed action from 'Deprecated: Generate' to 'Generate Application' with updated description.
• Introduced new inputs for sample name and database type in the action configuration.
• Replaced script-based generation steps with action-based steps for initializing the environment, generating sample configuration, and generating the project.
• Added constants for sample generation, sample name, and database type in the generator.
• Implemented logic to generate sample configurations and entities based on the selected database type in the generator class.

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• All continuous integration tests are green
• Tests are added where necessary
• The JDL part is updated if necessary
• jhipster-online is updated if necessary
• Documentation is added/updated where necessary
• Coding Rules & Commit Guidelines as per our CONTRIBUTING.md document are followed

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[Tcharl]

I can't check this one (not enough knowledge): with my knowledge I can just verify that the overall CI did not change? @qmonmert @mshima ?

[mshima]

We do have shared actions in https://github.com/jhipster/actions and have jhipster github-build-matrix command.
In the issue we don't need to create new shared actions, but use those supported actions like in https://github.com/jhipster/generator-jhipster/blob/main/.github/workflows/angular.yml.

Make sure that those actions are used in:

• workflows in generator-jhipster
• https://github.com/jhipster/jhipster-bom
• https://github.com/hipster-labs/jhipster-daily-builds
• blueprint (probably ok already)

Most of .github/actions should be dropped too.