convert DnD code to baseless and minimal dependencies

[bill]

In [26959]:

Convert DnD code to have granular dependencies and to be baseless.

These files are still pretty messy, as they don't obey namespaces well. For example, Container.js adds multiple symbols to dojo.dnd, in addition to defining the Container class.

Also removing these lines from mover.js, which do nothing given the typos of "Mover" instead of "Moveable":

dojo.dnd.constrainedMover = dojo.dnd.move.constrainedMover;
dojo.dnd.boxConstrainedMover = dojo.dnd.move.boxConstrainedMover;
dojo.dnd.parentConstrainedMover = dojo.dnd.move.parentConstrainedMover;

And also, some lint and spelling fixes.

Fixes #14201 !strict.

[liucougar]

In [26988]:

refs #14201: topic.unsubscribe is not available any more

!strict

[Mark Wubben]

In [27054]:

Fix dojo reference in dnd/Moveable. Refs #14201

[bill]

In [27950]:

remove lingering dojo reference, refs #14201 !strict.

[bill]

In [28250]:

stray dojo reference, refs #14201 !strict

[bill]

In [30372]:

convert DND test files to AMD, and stop using deprecated APIs, refs #14201

[bill]

In [30373]:

more conversion of DND test files to AMD, refs #14201

[bill]

In [30375]:

fix AMD conversion error and use data-dojo-type, refs #14201

[bill]

In [30404]:

need to wait for parser to finish before accessing c4, especially since dojo/dnd/Target is being auto-required, refs #14201