feat(server): in-place testnet creator (backport #19280) (#19405)

Co-authored-by: Adam Tucker <adam@osmosis.team>
Co-authored-by: marbar3778 <marbar3778@yahoo.com>
Co-authored-by: Julien Robert <julien@rbrt.fr>

CHANGELOG.md

@@ -38,6 +38,10 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## [Unreleased]
 
+### Features
+
+* (server) [#19280](https://github.com/cosmos/cosmos-sdk/pull/19280) Adds in-place testnet CLI command.
+
 ### Improvements
 
 * (client) [#19393](https://github.com/cosmos/cosmos-sdk/pull/19393/) Add `ReadDefaultValuesFromDefaultClientConfig` to populate the default values from the default client config in client.Context without creating a app folder.

baseapp/options.go

@@ -105,6 +105,11 @@ func SetChainID(chainID string) func(*BaseApp) {
 	return func(app *BaseApp) { app.chainID = chainID }
 }
 
+// SetStoreLoader allows customization of the rootMultiStore initialization.
+func SetStoreLoader(loader StoreLoader) func(*BaseApp) {
+	return func(app *BaseApp) { app.SetStoreLoader(loader) }
+}
+
 // SetOptimisticExecution enables optimistic execution.
 func SetOptimisticExecution(opts ...func(*oe.OptimisticExecution)) func(*BaseApp) {
 	return func(app *BaseApp) {