Add storage bounds to account procedures

[bobbinth]

Currently, we specify storage offsets for account procedures. That is, if storage offset for a procedure is 1, whenever the procedure tries to access storage item 0, the actual item accessed will be 1, when i tries to access storage item 1, the actual accessed item will be 2 etc. This puts a "lower bound" on the item a procedure can access - but we do not restrict the upper bound. That is, a procedure can access any storage item (up to a max of 255) starting from its offset.

It would be good to make sure that a given procedure can access only a specific set of storage items. This would prevent potential overlaps between different procedures. To do this, we need to do the following:

Update the AccountProcedureInfo struct to look something like this:

pub struct AccountProcedureInfo {
    mast_root: Digest,
    storage_offset: u8,
    storage_size: u8,
}

Where storage size would be the number of storage slots a procedure can access. So, the "physical" storage slots accessible by a procedure would be bounded by [storage_offset, storage_offset + storage_size).

We would also need to update the transaction kernel to handle this properly.

[bobbinth]

Largely closed by #886.

@phklive - could you create an issue (unless it already exists) on what remains to be done to remove the temporary code?