Introduce video state bloat bond

Dependency

https://github.com/Joystream/joystream/issues/3607

Proposal

Currently missing, this means creating a video, without any storage assets, will generate no state bond, but it will take up space in storage. This is unlike channels, which have to have a storage bag created, so there is at least a proportional state cost, but it may be slightly too low, however that is acceptable. Fund with membership of caller, even if curator group or lead.

Technical note: As highlighted by @shamil-gadelshin, being able to introdue this requires the ability of the content pallet extrinsics to do balance sufficiency checks, before mutation, which covers the requirements of now itself and the storage directory, which requires a bond per data object. Hence some pallet method, like total_bloat_bond_required(...) -> Balane, has to be introduced that returns the cost required for the storage pallet. The content pallet can then add this to its own costs, and do a total balance check before it starts any mutation.

┆Issue is synchronized with this Asana task by Unito