Fix [crate] Make Model Connection as newtype u64

[DaviRain-Su]

Closes: #543

Description

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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

Patch coverage: 77.41% and project coverage change: -0.07 ⚠️

Comparison is base (e7f02ac) 72.90% compared to head (709584c) 72.84%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #544      +/-   ##
==========================================
- Coverage   72.90%   72.84%   -0.07%     
==========================================
  Files         126      126              
  Lines       15594    15597       +3     
==========================================
- Hits        11369    11361       -8     
- Misses       4225     4236      +11     

Impacted Files	Coverage Δ
...src/core/ics04_channel/events/packet_attributes.rs	10.55% <0.00%> (-0.27%)	⬇️
.../src/core/ics04_channel/handler/acknowledgement.rs	87.08% <0.00%> (ø)
.../ibc/src/core/ics04_channel/handler/recv_packet.rs	87.41% <0.00%> (ø)
crates/ibc/src/core/ics24_host/error.rs	0.00% <ø> (ø)
crates/ibc/src/core/ics24_host/identifier.rs	60.61% <44.44%> (-1.77%)	⬇️
crates/ibc/src/core/ics04_channel/channel.rs	54.07% <50.00%> (ø)
.../src/core/ics04_channel/handler/chan_close_init.rs	81.48% <50.00%> (ø)
...c/core/ics04_channel/handler/chan_close_confirm.rs	91.37% <75.00%> (ø)
...bc/src/core/ics04_channel/handler/chan_open_try.rs	89.86% <75.00%> (ø)
...bc/src/core/ics04_channel/handler/chan_open_ack.rs	94.33% <80.00%> (ø)
... and 25 more

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[plafer]

Unfortunately, we'll have to close this as this is not a desired change (see comment in issue)