Restructure the default ~/.kaspad directory layout

[svarogg]

This PR resolves #1512

[codecov]

Codecov Report

Merging #1613 (b5c714e) into v0.10.0-dev (b84080f) will decrease coverage by 0.00%.
The diff coverage is 16.66%.

@@               Coverage Diff               @@
##           v0.10.0-dev    #1613      +/-   ##
===============================================
- Coverage        60.01%   60.01%   -0.01%     
===============================================
  Files              515      515              
  Lines            20454    20454              
===============================================
- Hits             12276    12275       -1     
- Misses            6227     6229       +2     
+ Partials          1951     1950       -1     

Impacted Files	Coverage Δ
app/app.go	0.00% <0.00%> (ø)
infrastructure/config/config.go	11.11% <20.00%> (-0.40%)	⬇️
app/protocol/flows/blockrelay/handle_relay_invs.go	68.75% <0.00%> (-1.25%)	⬇️
infrastructure/network/addressmanager/store.go	78.30% <0.00%> (+1.88%)	⬆️

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[elichai]

HmmHomeDir usually referes to ~/($HOME). I'd prefer we stayed with the "datadir" terminology