Resilience against `bitcoind` outages

[elsirion]

• Before starting consensus, wait for bitcoind to be reachable and synced
• Also check that bitcoind is on the same network as the config says
  • Either depends on #5121
  • Or we need a pre_check fn in the server module interface such that each module can attest that all its prerequisites are met. This also benefits other modules that have different external dependencies.
• We already shut down on bitcoind becoming unreachable, so we'll run into the above-mentioned functionality after being auto-restarted by e.g. sytemd. We should probably make this behavior faster.

This prevents AlephBFT from running into exponential slowdown in case bitcoind isn't reachable for a prolonged time.

[elsirion]

Less of a priority due to https://github.com/fedimint/fedimint/pull/7523