Simplify env/*.json creation

[lemunozm]

Right now the steps are:

1. Run deployment script
   1. Creates custom env/latest/<chainid>-latest.json file (through JsonRegistry)
      1. This step stores the contract addresses and version per contract
   2. Creates the default broadcast/<script>.s.sol/<chainid>/latest.json
2. Run update_network_config.py
   1. Reads env/latest/<chainid>-latest.json
   2. Reads broadcast/<script>.s.sol/<chainid>/latest.json
   3. Populates env/<netwok>.json file

We don't need env/latest/<chainid>-latest.json and JsonRegistry. We can get the contract addresses from the broadcast file, and we can just write the versioning in the own broadcast/<script>.s.sol/<chainid>/latest.json after stopBroadcast(). With this, we have just one file with all the deployment information. update_network_config.py can later read one file.

Benefits:

• Easier to infer from where the values come.
• Only one single file that we can share by just copying the file after a new deployment.
• Simplify deployment scripts