[🚜WIP] Custom config with custom logger

[rumkin]

🛑 THIS IS A DRAFT PR! Do not review it or merge! It conflicts with #176 which should be merged first.

This PR introduces custom config files for client from #171. It contains new CLI argument config which refers to custom configuration file.

[codecov[bot]]

Codecov Report

Merging #177 into master will decrease coverage by 0.76%. The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #177      +/-   ##
==========================================
- Coverage   74.66%   73.90%   -0.77%     
==========================================
  Files          45       40       -5     
  Lines        1508     1460      -48     
  Branches      199      194       -5     
==========================================
- Hits         1126     1079      -47     
+ Misses        322      318       -4     
- Partials       60       63       +3     

Impacted Files	Coverage Δ
lib/rpc/validation.ts	80.95% <0.00%> (-8.24%)	:arrow_down:
lib/logging.ts	71.42% <0.00%> (-6.35%)	:arrow_down:
lib/rpc/modules/web3.ts	87.50% <0.00%> (-1.39%)	:arrow_down:
lib/util/index.ts	100.00% <0.00%> (ø)
lib/rpc/error-code.ts	100.00% <0.00%> (ø)
lib/service/lightethereumservice.ts	100.00% <0.00%> (ø)
lib/net/protocol/index.ts
lib/net/peer/index.ts
lib/rpc/modules/index.ts
lib/sync/fetcher/index.ts
... and 5 more

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