cmd(core): prompt improvements

[bobheadxi]

🎟️ Ticket(s): Closes #569

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👷 Changes

• improved cmd/core/input with new prompt builder, available via NewPrompt()
• move walkthrough helpers to respective packages
• added some missing (y/N) prompts

[codecov]

Codecov Report

Merging #663 into master will decrease coverage by 4.29%.
The diff coverage is 72.92%.

@@            Coverage Diff             @@
##           master     #663      +/-   ##
==========================================
- Coverage   55.55%   51.26%   -4.28%     
==========================================
  Files          69       74       +5     
  Lines        3478     3812     +334     
==========================================
+ Hits         1932     1954      +22     
- Misses       1300     1612     +312     
  Partials      246      246              

Impacted Files	Coverage Δ
cmd/provision/provision.go	0.00% <0.00%> (ø)
cmd/init.go	11.41% <44.83%> (ø)
cmd/core/utils/input/input.go	80.00% <92.11%> (+3.19%)	⬆️
cmd/provision/input.go	100.00% <100.00%> (ø)
cmd/contrib.go	0.00% <0.00%> (ø)
cmd/root.go	0.00% <0.00%> (ø)

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