Notify users of async errors

Should notify users about async errors when syncing.

This PR includes:

It will also include stacked PRs once they are merged onto this one.

Feature 1

[x] Fresh install
[x] create sync account
[x] add few bookmarks and logins
[x] no warnings inside sync settings, no notifications
[x] If you don't have notifications permissions enabled, enable them
[x] apply patch attached to the asana task
[x] install the version
[x] make some changes on bookmarks and logins
[x] ensure warning message is shown in settings and you received a notification
[x] every time you enter in sync settings, we trigger sync, that should produce a random error which will replace existing one if any.
[x] Validate error copies

If limit exceeded:

message should say: Sync paused - You've reached the maximum number of (bookmarks|passwords). Please delete some to resume sync.
notification should say: (bookmarks|passwords) Sync is Paused - You've reached the maximum number of (bookmarks|passwords). Please delete some (bookmarks|passwords) to resume sync.

If it's bad request:

message should say: Sync paused - Some (bookmarks|passwords) are formatted incorrectly or too long and were not synced.
notification should say: (bookmarks|passwords) Sync is Paused - Some (bookmarks|passwords) are formatted incorrectly or too long and were not synced.

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duckduckgo / Android