Small refactoring of one folder, if it makes sense I could extend the scope.
* Remove some cloning (real and just verbosity in the code)
* Naming conventions like to/into*
* Some Clippy's suggestions
I found that we don't use field init shorthand syntax, so I didn't touch this part, was it discussed before?
* Beginning to remove in-process miner
* rustfmt
* rustfmt
* rustfmt
* rustfmt
* remove pow crate and put remnants into core
* rustfmt
* fix test compilation in core and chain
* rustfmt
* Updating server tests to use test miner
* rustfmt
* rustfmt
* remove pow from test matrix
* adding basic stratum stats to TUI
* run stratum server at all times, and halt messages while syncing
* fix core tests
* add ability to run internal test miner for cuckoo 16 testing
* modify build instructions
