[FEATURE]: Chain-specific .koinosrc

### Is there an existing issue for this?

- [X] I have searched the existing issues

### New feature

It would be great if .koinosrc allowed you to specify multiple configurations based on chain ID.

```
[mainnet]:
register mycontract AAA
register name_service BBB

[testnet]:
register mycontract CCC
register name_service DDD

[custom-chain-id]:
register mycontract EEE
register name_service FFF

[all]:
register_system_contracts
```

`register_system_contracts` would be shorthand for registering all the contracts returned by name_service (probably deserves its own feature request--not required for this). This scheme would make it much easier to use CLI, but it would also necessitate re-running .koinosrc commands every time the user disconnects/connects. Which would also mean unregistering addresses automatically.

### Anything else?

_No response_

Begin by locating how .koinosrc commands are parsed and how the CLI handles chain connect and disconnect events. Review the proposed mainnet, testnet, custom-chain-id, and all sections, including automatic unregistering. Done means configurations are selected by chain ID and reapplied after reconnection without requiring manual address cleanup.

Written by the indexing model from the issue text.