Add option to store blocks fields as json

[mattiaz9]

Right now blocks are stored in their own tables which for me it's an overkilled feature with some performance issues.

I'm in fact experiencing memory leaks when running a project with a lot of blocks and blocks fields. I believe the problem is caused by drizzle db-push not payload itself, but still having all those tables and relationships can't be good anyway in term of performance.

I'm wondering if you could add the ability to store the blocks data into as a json field.