Add in-place-testnet command

[codchen]

Describe your changes and provide context

(sei-chain PR: sei-protocol/sei-chain#2063)
To use:

1. modify ~/.sei/config/config.toml: change mode to validator and turn off statesync
2. run `seid in-place-testnet

Testing performed to validate your change

[codecov]

Codecov Report

Attention: Patch coverage is 1.07914% with 275 lines in your changes missing coverage. Please review.

Project coverage is 54.58%. Comparing base (faf3ee3) to head (77c8bef).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
server/in_place.go	0.00%	264 Missing ⚠️
baseapp/options.go	0.00%	4 Missing ⚠️
server/util.go	0.00%	3 Missing ⚠️
baseapp/baseapp.go	0.00%	2 Missing ⚠️
x/staking/keeper/keeper.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #561      +/-   ##
==========================================
- Coverage   54.85%   54.58%   -0.28%     
==========================================
  Files         631      632       +1     
  Lines       54951    55228     +277     
==========================================
+ Hits        30146    30148       +2     
- Misses      22647    22922     +275     
  Partials     2158     2158              

Files with missing lines	Coverage Δ
server/start.go	21.42% <100.00%> (+0.41%)	⬆️
baseapp/baseapp.go	65.48% <0.00%> (-0.18%)	⬇️
x/staking/keeper/keeper.go	73.80% <0.00%> (-3.70%)	⬇️
server/util.go	42.20% <0.00%> (-0.42%)	⬇️
baseapp/options.go	45.71% <0.00%> (-1.07%)	⬇️
server/in_place.go	0.00% <0.00%> (ø)