Adapting Prisma for the new structure

[sodic]

Fixes #1596

Tasks:

• Modify the generator to list prisma as a dependency in the project's package.json file.
• Decide where to list the @prisma/client dependency. - I put it in SDK and everything seems to work OK.
• Verify all Prisma operations successfully execute at the project's top level.
• Verify everything's OK with the types and the IDE support. - Check this again when generating the SDK code using the generator.
• Verify everything builds properly

How to run and test stuff:

• Go to waspc/examples/todo-typescript and work inside that project.
• Running ./cleanstart will clean everything, fix known issues (e.g., duplicate react) and start the app with all the necessary migrations applied.
• The rest of the commands (e.g,. cabal run wasp-cli start, cabal run wasp-cli clean) will do what you expect.
• After each change, either let the application pick it up, rerun cabal run wasp-cli start, or run ./cleanstart (depending on what you're changing).
• You can run ./fix to fix the double react installation issue (but often won't need to, as ./cleanstart takes care of it).
• Please don't commit the migrations or package-lock.json.

Important

PR 1603 (filip-wasp-reset) branches out of PR 1604 (filip-restructuring-prisma), which branches out of PR 1602 (filip-project-install-step).
The PR numbers are unfortunately out of order.
Make sure you keep the branches up to date with their bases as you change stuff.

[Martinsos]

Fixed the comments, didn't try running anything yet to see if everything works fine tried running it, everything seems to work fine!