For the XBlocks types that use legacy XModule-style assets (specifically, those that
inherit from `HTMLSnippet`), this is small refactor that brings them a bit closer to being like
standard XBlocks.
Given these class attributes:
class SomeXModuleLikeBlock(..., HTMLSnippet, ...):
...
studio_view_css = { ... }
preview_view_css = { ... }
studio_view_js = { ... }
preview_view_js = { ... }
...
we make it so their values are *paths to the resources*
rather than *the actual content of the resources*.
This is a no-op change, but it'll enable future XModule
asset refactorings which require us to operate on asset
paths rather than contents.
Part of: https://github.com/openedx/edx-platform/issues/32292
