Fix offline file loading logic

[vargaat]

What happened?

It seems that at some point during the offline file support delivery we broke the support for offline files when they are opened via a course's Files or Modules menu. The logic to load such offline files was non-existing so I implemented it.

refs: MBL-17935
affects: Student
release note: Fixed downloaded files not being available in offline mode.

test plan:

• Have a course with a course file added to modules.
• Sync the course with files for offline mode.
• Go offline.
• Enter the course's Files menu.
• Check if the downloaded file displays in the file viewer.
• Go to Modules, test if the linked file in the module item it will display in offline mode.
• Test if course files (both embedded and linked) in rich content are working in offline mode.
• Smoke test if files are working in online mode.

Checklist

• Follow-up e2e test ticket created
• Tested on phone
• Tested on tablet

[inst-danger]

Student Build QR Code:

[inst-danger]

Release Note:

Fixed downloaded files not being available in offline mode.

Affected Apps: Student

MBL-17935

Coverage	New %	Master %	Delta
Canvas iOS	91.7%	91.71%	-0.01%

Generated by 🚫 dangerJS against e4905d7

[rh12]

One edge case, may or may not need a fix:

1. In current app version (before this PR) I've synced offline content (used account in ticket)
2. Went offline
3. Checked that files do not load (as ticket describes), also entered the page with the embedded images
4. Embedded images were visible
5. Installed PR build + went offline again
6. Entered the page with the embedded images
7. The embedded images were not displaying (but the links work), even though the images are viewable in modules or module-files tab.

After I synced again, this issue was gone, embedded images were visible.

All else worked as described with or without resyncing.

[vargaat]

After I synced again, this issue was gone, embedded images were visible.

I experienced the exact same behavior. I think it's not related to this PR since offline RCE content rendering happens outside of this file that I modified. I'll take a deeper look on this and create a separate ticket if necessary.

[rh12]

After I synced again, this issue was gone, embedded images were visible.

I experienced the exact same behavior. I think it's not related to this PR since offline RCE content rendering happens outside of this file that I modified. I'll take a deeper look on this and create a separate ticket if necessary.

Thanks! In that case QA + 1

[ndrsszsz]

QA +1