feat: add total-borrowed query

[toteki]

closes: #1071

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Author Checklist

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I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
• added appropriate labels to the PR
• targeted the correct branch (see PR Targeting)
• provided a link to the relevant issue or specification
• added a changelog entry to CHANGELOG.md
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Reviewers Checklist

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I have...

• confirmed the correct type prefix in the PR title
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
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• reviewed tests and test coverage
• manually tested (if applicable)

[codecov-commenter]

Codecov Report

Merging #1099 (1403237) into main (1caed7c) will increase coverage by 0.00%.
The diff coverage is 43.63%.

@@           Coverage Diff           @@
##             main    #1099   +/-   ##
=======================================
  Coverage   43.54%   43.55%           
=======================================
  Files          65       65           
  Lines        8336     8390   +54     
=======================================
+ Hits         3630     3654   +24     
- Misses       4456     4486   +30     
  Partials      250      250           

Impacted Files	Coverage Δ
x/leverage/client/cli/query.go	0.00% <0.00%> (ø)
x/leverage/keeper/grpc_query.go	5.67% <0.00%> (-0.10%)	⬇️
x/leverage/client/tests/tests.go	100.00% <100.00%> (ø)