Abstract away file path creation in DefaultStoreConfiguration

[coderabbitai]

In the file debugger/server/src/commonMain/kotlin/pro/respawn/flowmvi/debugger/server/arch/configuration/DefaultStoreConfiguration.kt, there is a TODO comment to abstract away the file path creation logic:

// TODO: Abstract away
path = File("states").apply { mkdirs() }.resolve(".json").absolutePath,

This abstraction will improve modularity and reusability of the code.

Related PR: //pull/96
Comment: //pull/96#discussion_r1755641491

Requested by: @Nek-12