feat: add From derive for ICS26 messages

[mina86]

Add derive_more::From to MsgEnvelope and encapsulated enums so that
it’s easier to construct those objects without having to spell out
their names or variants.

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PR author checklist:

• Added changelog entry, using unclog.
• [-] Added tests.
• [-] Linked to GitHub issue.
• [-] Updated code comments and documentation (e.g., docs/).
• Tagged one reviewer who will be the one responsible for shepherding this PR.

Reviewer checklist:

• Reviewed Files changed in the GitHub PR explorer.
• Manually tested (in case integration/unit/mock tests are absent).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (553bc79) 67.65% compared to head (6b44b25) 67.73%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #938      +/-   ##
==========================================
+ Coverage   67.65%   67.73%   +0.07%     
==========================================
  Files         130      130              
  Lines       16415    16397      -18     
==========================================
  Hits        11106    11106              
+ Misses       5309     5291      -18     

Files	Coverage Δ
crates/ibc/src/core/ics02_client/msgs.rs	88.88% <100.00%> (ø)
crates/ibc/src/core/ics03_connection/msgs.rs	86.66% <100.00%> (ø)
crates/ibc/src/core/ics04_channel/msgs.rs	77.27% <100.00%> (ø)
crates/ibc/src/core/msgs.rs	1.03% <100.00%> (ø)

... and 7 files with indirect coverage changes

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[Farhad-Shabani]

Thanks for submitting this PR. That's fine with us, but before we go:
Could you provide us with the specific location where you have constructed the message in this manner?
To provide some context, historically, the conversion flow for nearly all use cases has involved decoding an incoming IBC message from a proto/raw message and subsequently crafting the corresponding domain IBC message type. (So, this newly derived From shouldn't be needed) Hence, any information that helps us coming up with a more versatile entry point is appreciated.

[mina86]

So far I’ve needed those specific conversion function in unit tests where I craft the messages by hand. Having said that, my current smart contract code (written for Solana using Anchor) expects the message to be borsh-serialised (which is what Anchor uses).