feat: multi message rust

[ibrizsabin]

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• I have performed a self-review of my own code
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[codecov]

Codecov Report

Merging #171 (28b1eb4) into development/177-xcall-future-proof-messaging (6171a6c) will decrease coverage by 3.97%.
The diff coverage is 61.80%.

❗ Current head 28b1eb4 differs from pull request most recent head f223dde. Consider uploading reports for the commit f223dde to get more accurate results

Additional details and impacted files

@@                                Coverage Diff                                 @@
##             development/177-xcall-future-proof-messaging     #171      +/-   ##
==================================================================================
- Coverage                                           70.39%   66.42%   -3.97%     
- Complexity                                             36       61      +25     
==================================================================================
  Files                                                  34       37       +3     
  Lines                                                1888     2088     +200     
  Branches                                               10       29      +19     
==================================================================================
+ Hits                                                 1329     1387      +58     
- Misses                                                553      687     +134     
- Partials                                                6       14       +8     

Flag	Coverage Δ
rust	64.44% <50.94%> (-3.16%)	⬇️
solidity	65.02% <ø> (-16.46%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
contracts/cosmwasm-vm/cw-xcall/src/assertion.rs	71.18% <100.00%> (-20.34%)	⬇️
contracts/cosmwasm-vm/cw-xcall/src/execute_call.rs	78.57% <100.00%> (ø)
contracts/cosmwasm-vm/cw-xcall/src/lib.rs	27.77% <ø> (ø)
contracts/cosmwasm-vm/cw-xcall/src/types/result.rs	52.30% <100.00%> (ø)
...acts/cosmwasm-vm/cw-xcall/src/send_call_message.rs	96.72% <96.00%> (+0.05%)	⬆️
...ontracts/cosmwasm-vm/cw-xcall/src/types/message.rs	43.28% <54.54%> (-4.67%)	⬇️
...ontracts/cosmwasm-vm/cw-xcall/src/types/request.rs	76.00% <73.68%> (-1.97%)	⬇️
...ts/cosmwasm-vm/cw-xcall/src/handle_call_message.rs	8.91% <0.00%> (ø)
...tracts/cosmwasm-vm/cw-xcall-lib/src/message/mod.rs	57.14% <57.14%> (ø)
...s/cosmwasm-vm/cw-xcall-lib/src/message/msg_type.rs	50.00% <50.00%> (ø)
... and 4 more

... and 4 files with indirect coverage changes

[AntonAndell]

Looks like it would work with the same flow internally. But implementing a new message type seems complicated and the flow is somewhat hard to follow. You can't really see what each message does clearly