Branch SonarCloud to angular-stdlib

[magnasilvar]

Add mecanism to launch automatically (via GitHub Actions) Sonar builds (https://sonarcloud.io/) to all angular-stdlib projects (only date right now) on :

• Master branch after a commit
• All others branches after a commit

Finally, add these relevant badges to angular-stdlib/README :

• Sonar Tests (ex: https://shields.io/category/build)
• Sonar Quality Gate (ex: https://shields.io/category/analysis)
• Sonar Coverage (ex: https://shields.io/category/coverage)

Help :

• https://sonarcloud.io/documentation/integrations/github/
• https://github.com/SonarSource/sonarcloud-github-action

Refs #16

[magnasilvar]

@KongrooParadox for information:

• Deadline has been postponed to v0.4.0.
• Moreover this issue is strongly linked with On push add GitHub Actions "build" & "test" #16.

[KongrooParadox]

Requirements to complete this issue:

• Generation of Sonarcloud security token
• Set SONAR_TOKEN environment variable in the "Secrets" settings page of angular-stdlib repository

[KongrooParadox]

Automatic analysis also has to be disabled for angular-stdlib project in sonarcloud

Source : https://community.sonarsource.com/t/how-to-disable-auto-scan/20941/9