Merge bitcoindevkit/bdk#683: Fix wallet sync for `RpcBlockchain`

5eeba6cced9a6fa0ad8ee4f64d04e1948620eac8 Various `RpcBlockchain` improvements (志宇)
5eb74af41494b7ec4894d7da3015da2981639228  Rpc: Manually add immature coinbase utxos (志宇)
ac19c19f21fce43a99ecf0c4f95ae818b620558c New `RpcBlockchain` implementation with various fixes (志宇)

Pull request description:

  Fixes #677

  ### Description

  Unfortunately to fix all the problems, I had to do a complete re-implementation of `RpcBlockchain`.

  **The new implementation fixes the following:**
  * We can track more than 100 scriptPubKeys
  * We can obtain more than 1000 transactions per sync
  * Transaction "metadata" for already-syned transactions are updated when we introduce new scriptPubKeys

  **`RpcConfig` changes:**
  * Introduce `RpcSyncParams`.
  * Remove `RpcConfig::skip_blocks` (this is replaced by `RpcSyncParams::start_time`).

  ### Notes to the reviewers

  * The `RpcConfig` structure is changed. It will be good to confirm whether this is an okay change.

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)
  * [x] I ran `cargo fmt` and `cargo clippy` before committing

  #### New Features:

  ~* [ ] I've added tests for the new feature~
  * [x] I've added docs for the new feature
  * [x] I've updated `CHANGELOG.md`

  #### Bugfixes:

  * [x] This pull request breaks the existing API
  * [x] I've added tests to reproduce the issue which are now passing
  * [x] I'm linking the issue being fixed by this PR

ACKs for top commit:
  afilini:
    ACK 5eeba6cced9a6fa0ad8ee4f64d04e1948620eac8

Tree-SHA512: 7e0c9cfc4ef10fb07e4ac7f6fbf30cf28ca6395495c0237fa5bfa9a2fcbbd4d8ff980ffcf71ddd10bc052e4c07bc2c27f093dd3cd1c69cb29141455c693f2386