Summary

The storage keys for all components were moved from the top of state_ext modules into new storage::keys modules. The key values were updated to a consistent style.

Background

We wanted the keys to be easy to find and to follow a consistent pattern in terms of their values and locations.

Changes

• All key consts and functions were moved to <COMPONENT>/storage/keys.
• All keys were given a prefix matching the component name followed by a /.
• All keys now use full words (except for a few instances of well-know abbreviations like "init") and _ as word separators.
• Existing helper structs in various state_ext modules for formatting keys were unified into a new struct AddressPrefixer in crate::storage.
• The Asset functionality was moved from crate::storage_keys to crate::storage.

Testing

• All keys have snapshot tests (including const keys - this might be considered overkill?)
• All keys have tests ensuring they have a component name as prefix.
• All prefix consts or functions which are used in state_ext modules are tested to ensure they are actually prefixes of the given keys.

Breaking Changelist

• This breaks the on-disk format of both the verifiable and non-verifiable store.

Related Issues

Closes #1611.