Deduplicate code for fetching stream info when sparse

[Stypox]

What is it?

• Bugfix (user facing)
• Feature (user facing)
• Codebase improvement (dev facing)
• Meta improvement to the project (dev facing)

Description of the changes in your PR

As explained in #7941 the method to fetch stream info item if sparse and to fetch uploader url if missing worked basically the same way, by fetching the StreamInfo if needed. This PR unifies those two methods in SparseItemUtil. They now show a toast with the correct information ("Fetching stream details" instead of "Fetching channel details"), and does so not only when loading uploader url but also when loading stream info before (en)queueing. I also fixed the way streams are saved to database: instead of only saving the channel url or saving the whole stream but setting its watch duration to 0 uselessly, now the stream info is upserted in the DB fully and without side effects. I also removed an unused related string.

Fixes the following issue(s)

• Fixes Duplicated methods that fetch full info for sparse streams #7941

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR.

Due diligence

• I read the contribution guidelines.

[AudricV]

Note that I didn't really take a look at the real code in my review, one about it is necessary.

[Stypox]

@TiA4f8R I disagree with all of your review except for the @NonNull and possibly the alignment of the parameters ;-)

[litetex]

LGTM, only one minor thing.

Btw how can I test the changes?

[Stypox]

I solved or answered your comments, thank you for the reviews

[litetex]

@Stypox
I think you didn't answer my questions and suggestions...

[Stypox]

Oh, I missed the "how can I test the changes" (but I did implement the suggestion and forgot to push it, see latest commit). Shall I create a database in which the feed has some items with missing data?

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

0.0% Coverage
0.0% Duplication

[litetex]

Oh, I missed the "how can I test the changes" (but I did implement the suggestion and forgot to push it, see latest commit). Shall I create a database in which the feed has some items with missing data?

You can if you want 😄

[Stypox]

Here it is: just import, open the feed fragment and reload the feed and you will get a bunch of videos with missing data. If you then want to test videos with all data, just disable fast loading and reload. NewPipeData-20220316_112803.zip

[litetex]

LGTM

Code ✔️
Test ✔️