Using Prisma file alongside Wasp

[infomiho]

This is some highly experimental work to move entities outside of the Wasp file and to put them in a regular schema.prisma file.

In this PR we:

• extend the model parser to parse lists of Prisma models
• extend the PSL parser to include enums
• parse the Prisma file and:
  • store the Prisma schema in AppSpec
  • inject the entities from Prisma file to the Wasp AST
• extend the LS to watch and parse the Prisma file as well
• we use DB extensions from the Prisma file directly
• we use the DB provider from the Prisma file directly

Closes #2002 Closes #2137

Left to do

• [ ] Validate the Wasp AST to ensure users don't define entities in the Wasp file? We are not sure if we want to do this
• [x] Make sure that validating schema.prisma in node_modules doesn't throw an error openBinaryFile: does not exist (No such file or directory
• [x] Make sure to regenerate the schema.prisma file if it changes in the node_modules/ (i.e. user runs npx prisma command and alters the Prisma schema)
• [x] Make Wasp AI use the new structure (prompts, Prisma file handling) https://github.com/wasp-lang/wasp/pull/2080
  • [x] E2e tests https://github.com/wasp-lang/wasp/pull/2095
• [x] Basic template
• [x] Validate that user set env("DATABASE_URL") for DB url

Probably in a separate PR

• [x] Update the docs
  • [x] Data model docs
  • [x] Tutorial
  • [x] Any other part that mentions entities
• [x] Write new migration docs
• [ ] Starter templates
  • [ ] Embeddings template
  • [ ] Open SaaS template
  • [ ] Todo Typescript template
  • [ ] Example apps
  • [x] waspc/examples apps
  • [ ] examples/ apps
  • [x] headless tests app

[Martinsos]

Awesome stuff @infomiho ! Anything specific you want looked at at the moment, or is all good for now?