feat: implement special asset pairs

[toteki]

Continuation of #2150

Since this is built on top of the commits in 2150, the file diff will be a lot smaller once the 2150 is merged.

[codecov]

Codecov Report

Merging #2158 (445a9dd) into main (7f05ad4) will decrease coverage by 5.36%.
The diff coverage is 80.60%.

❗ Current head 445a9dd differs from pull request most recent head 49ba5cc. Consider uploading reports for the commit 49ba5cc to get more accurate results

@@            Coverage Diff             @@
##             main    #2158      +/-   ##
==========================================
- Coverage   75.38%   70.03%   -5.36%     
==========================================
  Files         100      147      +47     
  Lines        8025    11411    +3386     
==========================================
+ Hits         6050     7992    +1942     
- Misses       1589     2873    +1284     
- Partials      386      546     +160     

Impacted Files	Coverage Δ
ante/spam_prevention.go	75.92% <ø> (ø)
x/incentive/codec.go	47.82% <ø> (+9.89%)	⬆️
x/incentive/keeper/invariants.go	0.00% <0.00%> (ø)
x/incentive/keeper/update.go	52.11% <ø> (ø)
x/incentive/keys.go	100.00% <ø> (ø)
x/incentive/msgs.go	77.41% <ø> (-0.81%)	⬇️
x/incentive/params.go	89.28% <ø> (-10.72%)	⬇️
x/leverage/client/tests/suite.go	100.00% <ø> (ø)
x/leverage/client/tests/tests.go	100.00% <ø> (ø)
x/leverage/keeper/borrows.go	74.82% <ø> (-3.76%)	⬇️
... and 56 more

... and 52 files with indirect coverage changes