refactor!: remove GetState() on connection interface

[colin-axner]

Description

A step towards removing the connection interface. As a nice side affect it removes a lot of unnecessary casting

closes: #XXXX

Commit Message / Changelog Entry

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[codecov-commenter]

Codecov Report

Attention: 8 lines in your changes are missing coverage. Please review.

Comparison is base (7df8644) 81.50% compared to head (be83e04) 81.53%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5769      +/-   ##
==========================================
+ Coverage   81.50%   81.53%   +0.03%     
==========================================
  Files         199      199              
  Lines       15225    15191      -34     
==========================================
- Hits        12409    12386      -23     
+ Misses       2349     2338      -11     
  Partials      467      467              

Files	Coverage Δ
modules/core/03-connection/types/connection.go	79.10% <ø> (+2.29%)	⬆️
modules/core/04-channel/keeper/packet.go	99.09% <100.00%> (-0.02%)	⬇️
modules/core/04-channel/keeper/handshake.go	90.20% <80.00%> (+0.49%)	⬆️
modules/core/04-channel/keeper/upgrade.go	92.46% <70.00%> (+0.75%)	⬆️

[damiannolan]

Nice!

[DimitrisJim]

never noticed we do a cast to int and a cast back to the enum 😅 pretty nice cleanup!