v4 flutter bloc sample update

[vasilich6107]

Update of the bloc samples

Breaking changes

• No braking changes

Fixes / Enhancements

• Updated sample to use latest flutter_bloclib
• Extracted bloc stuff to external library

[codecov]

Codecov Report

Merging #736 into modularization will not change coverage.
The diff coverage is n/a.

@@               Coverage Diff               @@
##           modularization     #736   +/-   ##
===============================================
  Coverage           50.77%   50.77%           
===============================================
  Files                  34       34           
  Lines                1227     1227           
===============================================
  Hits                  623      623           
  Misses                604      604           

Flag	Coverage Δ
#graphql_client	54.71% <ø> (ø)
#graphql_flutter	31.57% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

---

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 715e6a4...b858a02. Read the comment docs.

[HofmannZ]

🎉 This PR is included in version 4.0.0-beta.1 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀

[HofmannZ]

🎉 This PR is included in version 4.0.0 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀