Remove generator v1 and v2 and switch to v3

[derberg]

This PR in generator release new v3 of Generator.

CLI already supports Generator v1 and v2

• Command https://github.com/asyncapi/cli/blob/master/src/apps/cli/commands/generate/client.ts uses only v2
• Command https://github.com/asyncapi/cli/blob/master/src/apps/cli/commands/generate/fromTemplate.ts users dedicated service that integrates v1 and v2. By default v1 is used, and v2 is used if flag is passed.

State:

• v1 is old, no need to keep it.
• imho v2 can be removed as well because nunjucks was deprecated over a year ago, people had a lot of time to migrate

My proposal is to switch to generator v3, remove v1 and v2 and release CLI Major.

WDYT? I can work on PR for that

[derberg]

cc @Souvikns @Amzani @Shurtu-gal @AayushSaini101

as I wrote, I can work on a PR

[Shurtu-gal]

I agree with this. Maintaining two versions was a headache.