fix: fix genesis and support abstain

[0Tech]

Description

This patch fixes bugs on x/foundation:

1. fix unpacking of the foundation info.
2. support abstain option (where the policy is percentage type).

Checklist:

• I followed the contributing guidelines and code of conduct.
• I have added a relevant changelog to CHANGELOG.md
• I have added tests to cover my changes.
• I have updated the documentation accordingly. [no need]
• I have updated API documentation client/docs/swagger-ui/swagger.yaml [no need]

[codecov]

Codecov Report

Merging #545 (97bcd3d) into main (1f94632) will increase coverage by 0.23%.
The diff coverage is 72.02%.

@@            Coverage Diff             @@
##             main     #545      +/-   ##
==========================================
+ Coverage   57.34%   57.58%   +0.23%     
==========================================
  Files         791      793       +2     
  Lines       86263    86584     +321     
==========================================
+ Hits        49469    49858     +389     
+ Misses      33644    33564      -80     
- Partials     3150     3162      +12     

Impacted Files	Coverage Δ
x/foundation/client/testutil/grpc.go	92.10% <ø> (-2.59%)	⬇️
x/foundation/codec.go	0.00% <0.00%> (ø)
x/foundation/keeper/grpc_query.go	4.34% <0.00%> (-14.01%)	⬇️
x/foundation/keeper/genesis.go	77.92% <52.54%> (+2.48%)	⬆️
x/foundation/genesis.go	76.19% <52.83%> (-3.18%)	⬇️
x/foundation/keeper/proposal.go	69.14% <60.00%> (-0.30%)	⬇️
x/foundation/keeper/grant.go	63.82% <63.82%> (ø)
x/foundation/foundation.go	80.50% <69.69%> (+42.10%)	⬆️
x/foundation/msgs.go	85.02% <77.35%> (+16.96%)	⬆️
x/foundation/keeper/keeper.go	83.33% <77.77%> (-8.67%)	⬇️
... and 21 more

[dudong2]

LGTM

[zemyblue]

LGTM