feat(consume): improve hive simulator cli ux

Currently, you "should" specify two values when building an eest simulator image:
1. `branch`
2. `fixtures`
to ensure compatibility and `branch=` is required to avoid turbulence on `main`.

E.g.,
```
./hive -client reth --sim "ethereum/eest" --sim.buildarg fixtures=https://github.com/ethereum/execution-spec-tests/releases/download/v4.1.0/fixtures_develop.tar.gz --sim.buildarg branch=v4.1.0 -sim.timelimit 1s
```

While it's nice to have this flexibility and we should keep it, regular users should just be able to specify:

```
./hive -client reth --sim "ethereum/eest" --sim.buildarg version=v4.1.0
```

which would avoid confusion and potentially mis-matching EEST library and release versions (which is expected to happen, when the pydantic models used to define EEST test vectors get updated with backwards incompatible fields). I would use `fixtures_develop` by default.

Such an interface would probably avoided the issues recently experienced in reth's ci, cf
- https://github.com/paradigmxyz/reth/pull/15274