fix(sysdetails): Fixes css issue on sysDetails page

[adonispuente]

There was an issue on sysdetails page where when navigating from inventory, and going to vulnerability systems details page, a large gap would appear in between the detail header and the table.

This is a result of double inventory classes. Ive removed the class is this PR as its redundant, and gone in here, removed the class, and seperated the table from the header component.

RedHatInsights/insights-inventory-frontend#2235

[jira-linking]

Commits missing Jira IDs:
d6119b8

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 10 lines in your changes missing coverage. Please review.

Project coverage is 67.15%. Comparing base (985f798) to head (d6119b8).
Report is 1 commits behind head on master.

Files	Patch %	Lines
...tComponents/SystemDetailsPage/SystemDetailsPage.js	0.00%	10 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2130   +/-   ##
=======================================
  Coverage   67.15%   67.15%           
=======================================
  Files         128      128           
  Lines        3440     3440           
  Branches     1067     1067           
=======================================
  Hits         2310     2310           
  Misses       1130     1130           

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