Refactor get_account_id_from_seed / get_from_seed to one common place

[bkontur]

These functions are copied all over the place.

[bkontur]

check @kianenigma's comment here: #5327 (comment)

Keyring::iter() would give the same, but I donno why no one uses it 🤷

[programskillforverification]

I will work on this

[michalkucharczyk]

tagging @iulianbarbu , as I know he is working on similar matter.

[iulianbarbu]

thanks for the tag! I am happy to leave it to @programskillforverification. Leaving here the direction I got based on the comms on this subject lately and my own investigation.

There is a mention of adding sp_keyring as a frame dependency as noted here: #4739 (comment). My understanding is that the overall suggestion is to re-export sp_keyring::Keyring from frame and use Keyring::iter() instead of the widely used get_account_id_from_seed and friends. The re-export wouldn't be usable without importing frame everywhere we have the duplicated business logic (all places that implement/import get_account_id_from_seed/get_from_seed at least). These places have dependencies on sp-core and sp-runtime on their own, so we might very well remove them and use frame::deps::sp_core/sp_runtime instead where needed (hopefully feature flags will not cause issues here).