feat: add r/sys/params + params genesis support

[moul]

• [ ] add r/sys/params (dummy version?)
• [ ] add genesis/params.txt
• [ ] port some existing configurations

Depends on #2920

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 79.45205% with 30 lines in your changes missing coverage. Please review.

Project coverage is 63.78%. Comparing base (60304df) to head (1ce1a27). Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
gno.land/pkg/gnoland/genesis.go	59.45%	10 Missing and 5 partials :warning:
gno.land/pkg/gnoland/param.go	80.76%	12 Missing and 3 partials :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3003      +/-   ##
==========================================
+ Coverage   63.76%   63.78%   +0.01%     
==========================================
  Files         548      549       +1     
  Lines       78681    78819     +138     
==========================================
+ Hits        50171    50273     +102     
- Misses      25128    25154      +26     
- Partials     3382     3392      +10     

Flag	Coverage Δ
contribs/gnodev	61.16% <ø> (ø)
contribs/gnofaucet	14.82% <ø> (ø)
gno.land	73.70% <77.94%> (+0.07%)	:arrow_up:
gnovm	67.93% <100.00%> (+<0.01%)	:arrow_up:
misc/genstd	79.72% <ø> (ø)
tm2	62.41% <100.00%> (-0.02%)	:arrow_down:

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[moul]

I believe that Codecov has false negatives. It flags lines that are actually tested at least twice.

[moul]

Ready for review. The CI is red, but the new code is tested. The conflict is easy to fix, I'll fix it soon. Blocking #2911.