[Meta] Remove Elastic Agent V1 control protocol

Now that the V2 protocol is out from 8.3 on, the V1 will not be updated and thus removed in a few releases. (Around end of 2022)

https://docs.google.com/document/d/1wqBWAhFdao93h2SE__koisuOOMGbwA5DTXDVFSKFYBs/edit

### Parallel
- [x] Re-structure the binary layout for V2 to be flat (no tarball, compression, etc.)
- [ ] Change all beats to start without reading a configuration file from the disk (preferably they should start, context to control protocol and wait for initial configuration)
- [x] https://github.com/elastic/beats/issues/31901
- [ ] Change beats to understand configuration directly from policy (all rules are removed in the V2 binary specification)
- [x] https://github.com/elastic/beats/issues/31900
- [ ] Implement V2 control protocol in libbeat (having all beats using V2)
- [x] https://github.com/elastic/beats/issues/32078
- [ ] Implement V2 control protocol in Endpoint Security

### Sequential
- [x] Implement validation and reading of the V2 binary specification
- [x] Implement V2 control protocol server in Elastic Agent
- [x] Parse Elastic Agent policy with V2 binary specification to spawn Units and be controlled through the V2 protocol