chore: send slack notification on sample app build

[mrehan27]

part of: MBL-750

Changes

• Integrated common GitHub Action to send slack notifications when a sample app build completes
• Updated relevant GitHub Action and lane to extract necessary values for triggering the notification

Example messages can be seen in slack channels used for notifications

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 52.01%. Comparing base (8b30804) to head (2374d80).
Report is 49 commits behind head on main.

Additional details and impacted files

@@              Coverage Diff              @@
##               main     #496       +/-   ##
=============================================
+ Coverage     41.98%   52.01%   +10.03%     
- Complexity      259      318       +59     
=============================================
  Files            99      105        +6     
  Lines          2320     2855      +535     
  Branches        344      380       +36     
=============================================
+ Hits            974     1485      +511     
- Misses         1247     1257       +10     
- Partials         99      113       +14     

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[github-actions]

Build available to test
Version: mbl-750-app-slack-notify-SNAPSHOT
Repository: https://s01.oss.sonatype.org/content/repositories/snapshots/