feat: remove offset and size from AccountProcedureInfo

[PhilippGackstatter]

Rename AccountProcedureInfo into AccountProcedureRoot and remove storage offset and size.

• Reduces number of elements needed for each procedure in the kernel from 8 to 4.
• Remove storage offset and storage size which is no longer needed after named storage slots, as each component can access any storage slot by name.
• Updates account code docs and removes some unused and (imo) unnecessary methods like "find index by root", which is now easy to implement via AccountCode::procedures. Happy to bring these back if you have different opinions.
• Removes a lot of code 🎉
• Notably, the kernel now uses mem::pipe_words_to_memory instead of pipe_double_words_to_memory for hashing account code. This is less efficient, but I don't think we should enforce that the number of procedures is even?
• Previously, we used the storage_offset to detect procedures by the same account component in AccountComponentInterface. Then each component corresponded to one AccountComponentInterface::Custom entry. We can no longer differentiate components at the procedure level now, and so all procedures that are not well-known are put into a single AccountComponentInterface::Custom. Since we want to refactor this anyway, I assume this is not a big deal.

This addresses the remaining TODO(named_slots) and so this should close the named storage slots issue.

Follow-up: (note to self) Open issue for rearranging account memory to make all account sections contiguous.

closes #1724

[bobbinth]

Looks good! Thank you! I left some comments inline.

[bobbinth]

Looks good! Thank you! I left just one comment inline.