Remove Version interface and casting functions from 03-connection

[Reecepbcups]

Description

• Removes the exported.Version interface (legacy from GetVersions()) in favor of *Version type
• Removes ExportedVersionsToProto & ProtoVersionsToExported casting functions (and removed from single .md file)
• TODO Change log entry No need we will use the commit message to generate the changelog.

closes: #1690

Commit Message / Changelog Entry

imp: remove `Version` interface and casting functions from 03-connection

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• Targeted PR against correct branch (see CONTRIBUTING.md).
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
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• Wrote unit and integration tests.
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[codecov-commenter]

Codecov Report

Merging #4110 (f5c7937) into main (4e1e594) will increase coverage by 0.01%.
The diff coverage is 86.66%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4110      +/-   ##
==========================================
+ Coverage   79.45%   79.47%   +0.01%     
==========================================
  Files         188      188              
  Lines       12990    12973      -17     
==========================================
- Hits        10321    10310      -11     
+ Misses       2240     2234       -6     
  Partials      429      429              

Files Changed	Coverage Δ
modules/core/03-connection/types/codec.go	100.00% <ø> (ø)
modules/core/03-connection/types/connection.go	76.81% <0.00%> (ø)
modules/core/03-connection/keeper/handshake.go	88.58% <100.00%> (ø)
modules/core/03-connection/keeper/keeper.go	90.37% <100.00%> (ø)
modules/core/03-connection/types/version.go	96.38% <100.00%> (+5.85%)	⬆️
modules/core/keeper/msg_server.go	55.95% <100.00%> (ø)

[crodriguezvega]

Looks good to me; thank you, @Reecepbcups!

[colin-axner]

This makes me so happy! Thank you @Reecepbcups, great cleanup