This creates a the nano::store library/namespace/directory

[clemahieu]

Commits should be reviewed in sequence as they're grouped by change concept.

Major components that went into this PR:

• Clearing nano::store for use as a namespace by renaming nano::store to nano::store::component
• Moving nano::store header files and updating includes in implementation files
• Moving nano::store implementation files
• Extracting classes from large files into new files
• Renaming namespaces and classes

Move files to their new location with as few commits and as early as possible
Move files without modification to maintain history and mitigate merge conflicts
Don't move a file and change a file in the same commit