Prevent duplicate nodes from reconnect and refine reset to make sure deleted record is sent

[darkdh]

kSyncPrevSeed is saved when reset and then will be clear during OnSaveInitData for create/connect sync chain
ResetSyncInternal is introduced for making sure the final delete record is sent and resolved.

fix brave/brave-browser#2443
fix brave/brave-browser#2527

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Verified that these changes build without errors on
  • Windows
  • macOS
  • Linux
• Verified that these changes pass automated tests (npm test brave_unit_tests && npm test brave_browser_tests) on
  • Windows
  • macOS
  • Linux
• Ran git rebase master (if needed).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed.
• Add appropriate QA labels (QA/Yes or QA/No) to include the closed issue in milestone

Test Plan:

1. Create sync chain from device A and create bookmarks like this

f1 -|
    |- f2
    |- b1

2. Connect to the sync chain from device B and device C
3. Wait for devices list and bookmarks synced on all devices
4. Remove device C on device C by click "x" or "leave sync chain" (self deleted)
5. Make sure device C get deleted on device A and device B
6. Delete b1 from device A
7. Connect device C to the sync chain which contains device A and device B again
8. Make sure device C has bookmarks like this

f1 -|
    |- f2

9. Add b2 to device C to prove it is syncing with the sync chain like this

f1 -|
    |- f2
    |- b2

10. Make sure all devices have bookmarks like above structure
11. Remove device C on device C by click "x" or "leave sync chain" (self deleted)
12. Make sure device C get deleted on device A and device B
13. Create sync chain on device C and connect device D to it /create sync chain on device D and connect device C to it (Connect/Create different chain)
14. Make sure device D has bookmarks like this

f1 -|
    |- f2
    |- b2

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

[AlexeyBarabash]

++

[AlexeyBarabash]

This PR also addresses https://github.com/brave/browser-android-tabs/issues/924 .

[darkdh]

master: c5ee622
0.60.x: 27f2159

[rebron]

Deliberated with @kjozwiak. Marking approved for uplift to 59.x

[darkdh]

0.59.x: ddede29