Posts sync fixes

[RiccardoM]

Description

• Fixed a bug that caused the posts to never update their status when synced to the chain (closes #81).
• Fixed a bug that caused the home list to throw an exception due to a bad setState call

Checklist

• [x] Targeted PR against correct branch.
• [x] Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• [x] Wrote unit tests.
• [x] Run flutter format.
• [ ] Updated the documentation.
• [ ] Added an entry to the CHANGELOG.md file.
• [ ] Re-reviewed Files changed in the Github PR explorer.

[codecov[bot]]

Codecov Report

Merging #103 into master will increase coverage by 0.04%. The diff coverage is 54.28%.

@@            Coverage Diff             @@
##           master     #103      +/-   ##
==========================================
+ Coverage   17.51%   17.56%   +0.04%     
==========================================
  Files         261      261              
  Lines        6445     6456      +11     
==========================================
+ Hits         1129     1134       +5     
- Misses       5316     5322       +6     

Impacted Files	Coverage Δ
lib/sources/chain/chain_source_impl.dart	81.25% <0.00%> (-1.29%)	:arrow_down:
lib/ui/blocs/home/home_bloc.dart	0.00% <0.00%> (ø)
...dgets/post_content/widgets/link_preview/index.dart	0.00% <0.00%> (ø)
.../notifications/remote/models/fcm_message_data.dart	61.53% <66.66%> (+3.64%)	:arrow_up:
lib/sources/posts/local/local_posts_source.dart	88.14% <76.92%> (-2.01%)	:arrow_down:
lib/repositories/posts/posts_repository_impl.dart	94.82% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 943feb5...df7af27. Read the comment docs.