Factory: Refactor integration tests

[ueco-jb]

Work on branch factory/more-advanced-testcases.
main...factory/more-advanced-testcases

Changes that needs to be done:

• rename dependencies to match our own (dex::)
• pool configuration - LP share token requires a denom, not token code id
• keep pools in test as smart token - cw20
• remove placeholder mentiones, this is part of migration/instantiation we don't need (like store_placeholder_code function, test can_migrate_the_placeholder_to_a_factory_properly)
• s/pair/pool

[gangov]

note to self as per DM's: first make factory_helper.rs file compile, comment out the whole integration.rs and then continue by uncommenting on test per test basis