Paintroid-450 : Add share menu option in paint view

[vishad-tyagi]

Ticket
https://catrobat.atlassian.net/browse/PAINTROID-450
Paintroid-450 : Add share menu option in paint view

Description
Add "share" option to the paint view overflow menu.
This should open the phone native share window.

New Features and Enhancements

• New Features and Enhancements

Refactorings and Bug Fixes

• Refactorings and Bug Fixes

Checklist

Your checklist for this pull request

Please review the contributing guidelines and wiki pages of this repository.

• Include the name of the Jira ticket in the PR’s title
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• Include reasonable and readable tests verifying the added or changed behavior
• Confirm that new and existing unit tests pass locally
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[Lenkomotive]

The share package seems to be deprecated see here. Please always check if packages are maintained before adding them.

Also- add tests please :)

[vishad-tyagi]

@Lenkomotive I have changed the package to share_plus. and have added the tests also. while Native share windows cannot be tested in Flutter widget tests because these tests run in a Dart VM, that does not interact with native components. I have implemented a workaround of checking the entire widget tree before and after, looking for any unexpected behaviour and error dialog. If anything else needs to be changed let me know.
I will be careful in checking the package version from next time 😅

[msesko]

pls check my comments. thanks

[juliajulie95]

Thank you for the PR!
Please make sure the actual image that was drawn is shared with the share button, not just a text! :)

[vishad-tyagi]

@juliajulie95 I intended to do the same initially only but was waiting for additional info like the default format of shared images, whether manual image compression is required or not etc 🙂 , I tried to get more info on the Jira ticket only. So I ended up placing a text-only
Just let me know this info, I will get to work in some time (My uni end sem exams are going on 😅)

[juliajulie95]

Sorry for that.
Please share the currently displayed image. You might have to save it as a temp and then share that file

[bhav-khurana]

Are we still working on this ticket? @juliajulie95 @msesko
I can complete it if anything is pending