test(store): added test coverage for createStore with custom middleware chaining

[tmdeveloper007]

Summary of What Has Been Done

Added with 8 test cases covering createStore with custom middleware chaining.

Changes Made

• Created with 8 test cases:
  • Single middleware receives prevState and update correctly
  • Middleware can transform updates before passing to next()
  • Two middleware chain in correct order (first before second before, second after first after)
  • Middleware can access both prevState and nextState
  • Throwing in middleware correctly propagates the error
  • Middleware that does not call next() blocks state updates
  • Empty middleware array behaves like no middleware
  • Multiple sequential updates with middleware capture correct prevState snapshots

Impact it Made

• Documents the middleware API contract for custom middleware authors
• Ensures middleware chaining order is predictable
• Covers a critical extensibility feature that lacked test coverage

Closes Karanjot786#3293.

Note: please assign this PR to the tmdeveloper007 account.