WP Stories integration - setting the base error notification ID and setDelete PendingIntent for error notification

[mzorz]

Builds on top of #12045

This PR sets the base error notification ID from the WPAndroid app to avoid collision with PostUploadNotifier.
Also, implements the PendingIntent loader for when an error notification is dismissed, and keeps tracks
Finally, we added the following notification types:

    STORY_SAVE_SUCCESS,
    STORY_SAVE_ERROR,
    STORY_FRAME_SAVE_SUCCESS,
    STORY_FRAME_SAVE_ERROR;

of which currently only STORY_SAVE_ERROR is used / needed at this point.

To test:

0. setup some artificial error as we've been doing before in the stories library (use a counter so it fails only once)
1. create a story, add some text / emoji
2. save (tap publish)
3. observe the error notification appears.
4. tap retry to solve the issue
5. observe the error notification gets properly cancelled.

PR submission checklist:

• I have considered adding unit tests where possible.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

[peril-wordpress-mobile]

You can trigger optional UI/connected tests for these changes by visiting CircleCI here.

[peril-wordpress-mobile]

You can test the changes on this Pull Request by downloading the APK here.

[jd-alexander]

Thanks for these changes @mzorz I tested and I was able to reproduce the notification error. I added an Exception to the FrameSaveManager to simulate an error before an image frame was saved. LGTM 🚢