refactor(btcio): remove bitcoind_json_rpc_types

[storopoli]

It does not make sense to have this dep since we're already half-baking
our own custom types on top of it and using only a tiny minority of the
types as being the ones provided by bitcoind_json_rpc_types.

[storopoli]

One less dependency @delbonis.

[codecov]

Codecov Report

Attention: Patch coverage is 61.53846% with 5 lines in your changes missing coverage. Please review.

Project coverage is 57.73%. Comparing base (a2d835c) to head (4af0042).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/btcio/src/rpc/types.rs	61.53%	5 Missing ⚠️

@@            Coverage Diff             @@
##             main     #424      +/-   ##
==========================================
- Coverage   57.74%   57.73%   -0.01%     
==========================================
  Files         263      263              
  Lines       27538    27551      +13     
==========================================
+ Hits        15902    15907       +5     
- Misses      11636    11644       +8     

Files with missing lines	Coverage Δ
crates/btcio/src/rpc/client.rs	88.47% <ø> (ø)
crates/btcio/src/rpc/types.rs	53.08% <61.53%> (+0.73%)	⬆️

... and 5 files with indirect coverage changes