[AAP-52663] Add SonarCloud badges to README.md (ansible#856)

## Summary
Add comprehensive SonarCloud quality metrics badges to the README to
provide visibility into code quality, security, and maintainability
metrics.

## Changes
- Added 7 SonarCloud badges matching the format used in aap-gateway:
  - Quality Gate Status
  - Coverage
  - Vulnerabilities
  - Security Rating
  - Bugs
  - Code Smells
  - Maintainability Rating
- Also includes Makefile update with `check_imports` target from
upstream rebase

## JIRA
https://issues.redhat.com/browse/AAP-52663

All badges link to the `ansible_django-ansible-base` SonarCloud project
and provide direct links to detailed metrics.

Co-authored-by: Claude <[email protected]>

Author: john-westcott-iv

README.md

@@ -1,3 +1,11 @@
+[![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=ansible_django-ansible-base&metric=alert_status)](https://sonarcloud.io/summary/new_code?id=ansible_django-ansible-base)
+[![Coverage](https://sonarcloud.io/api/project_badges/measure?project=ansible_django-ansible-base&metric=coverage)](https://sonarcloud.io/summary/new_code?id=ansible_django-ansible-base)
+[![Vulnerabilities](https://sonarcloud.io/api/project_badges/measure?project=ansible_django-ansible-base&metric=vulnerabilities)](https://sonarcloud.io/summary/new_code?id=ansible_django-ansible-base)
+[![Security Rating](https://sonarcloud.io/api/project_badges/measure?project=ansible_django-ansible-base&metric=security_rating)](https://sonarcloud.io/summary/new_code?id=ansible_django-ansible-base)
+[![Bugs](https://sonarcloud.io/api/project_badges/measure?project=ansible_django-ansible-base&metric=bugs)](https://sonarcloud.io/summary/new_code?id=ansible_django-ansible-base)
+[![Code Smells](https://sonarcloud.io/api/project_badges/measure?project=ansible_django-ansible-base&metric=code_smells)](https://sonarcloud.io/summary/new_code?id=ansible_django-ansible-base)
+[![Maintainability Rating](https://sonarcloud.io/api/project_badges/measure?project=ansible_django-ansible-base&metric=sqale_rating)](https://sonarcloud.io/summary/new_code?id=ansible_django-ansible-base)
+
 # django-ansible-base
 
 ## What is it?

sonar-project.properties

@@ -156,4 +156,4 @@ sonar.issue.ignore.multicriteria.e1.resourceKey=**/migrations/**/*
 # sonar.java.skipUnchanged=false
 # sonar.scm.forceReloadAll=true
 # sonar.filesize.limit=100
-# sonar.qualitygate.wait=true
+# sonar.qualitygate.wait=true