Re-work REACT_APP_MIN_DEPOSIT_CLI_VERSION usage

Now that there are more audited versions of the staking-deposit-cli, it is time to rethink how we do ensure that the `deposit_data.json` was generated by a tool with sufficient features.

Currently, we use the `REACT_APP_MIN_DEPOSIT_CLI_VERSION` constant to ensure a minimum feature set, but this is awkwardly tied to the https://github.com/ethereum/staking-deposit-cli which noi longer seems appropriate.

One approach would be to have text-based features we add to ensure a minimum level of support and check for those (eg. `testnet-holesky, bug-fix-123`), but this feels a little over engineered for our current needs.

Personally I am partial to sticking with the numbering approach, but just agreeing with the ethstaker folks as to when we need to bump the version number. We could even maintain a doc in this repo that maps features to version numbers.

cc @remyroy @valefar-on-discord I'd love to hear your thoughts here.

Start by locating every use of REACT_APP_MIN_DEPOSIT_CLI_VERSION and the validation path for deposit_data.json. Review the audited staking-deposit-cli versions and the proposed feature or numbering approaches, then define an agreed replacement and document the feature-to-version mapping if that approach is chosen.

Written by the indexing model from the issue text.