Compact Block Filter chain source tracking issue #1165

The PR for CBF chain source has become huge and we've decided to split it into few smaller ones, especially as there are some independent changes there.

This issue is a tracker for the prerequisite PRs.

• Move ChainListener from chain::bitcoind to chain #1162 (we also use it in CBF)
• move electrum's fee estimation to chain/mod.rs . Electrum is a on option for fee source in CBF.
• make tests not implying the chain source coincides with the mining node (wait for tx and block propagation)
• not a direct dependency, but encountered the bug mentioned in this PR: Reconcile monitor tips before starting peers, sync Lightning wallets on startup #1161

The original PR had undergone surgeries and now directly depends the first three points from this list. Also comments in the PR are still valid and the description of changes there is up-to-date.