Add a new property of Crowd class

[ChowRex]

• Fix lxml CVE, using bs4 to replace.
• Add a property for Crowd class to retrieves full details of all group memberships.

[ChowRex]

Hi @gonchik !
As your said early (#1400 (comment)), I fixed this CVE by using bs4.

[codecov]

Codecov Report

Attention: Patch coverage is 23.07692% with 10 lines in your changes missing coverage. Please review.

Project coverage is 34.37%. Comparing base (b81fff5) to head (65f655c).
Report is 14 commits behind head on master.

Files	Patch %	Lines
atlassian/crowd.py	23.07%	10 Missing ⚠️

Additional details and impacted files

@@ Coverage Diff @@ ## master #1402 +/- ## ========================================== - Coverage 34.39% 34.37% -0.02%  ========================================== Files 46 46 Lines 8569 8582 +13 Branches 1598 1601 +3 ========================================== + Hits 2947 2950 +3  - Misses 5499 5509 +10  Partials 123 123 

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[gonchik]

@ChowRex Thank you!