ouia: use "contains" in xpath locator

[jrusz]

This allows to make widgetastic.patternfly5 ouia widgets backwards compatibl with PF4.

[jrusz]

@digitronik Hi, can you review this please? (For some reason I can't add reviewers)

[digitronik]

@jrusz unit tests ^^

[codecov]

Codecov Report

Merging #248 (bfdbe1c) into master (4366f0d) will not change coverage.
Report is 2 commits behind head on master.
The diff coverage is n/a.

❗ Current head bfdbe1c differs from pull request most recent head 6151030. Consider uploading reports for the commit 6151030 to get more accurate results

@@           Coverage Diff           @@
##           master     #248   +/-   ##
=======================================
  Coverage   86.45%   86.45%           
=======================================
  Files          18       18           
  Lines        2570     2570           
=======================================
  Hits         2222     2222           
  Misses        348      348           

Flag	Coverage Δ
unittests	86.45% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
src/widgetastic/ouia/__init__.py	92.30% <ø> (ø)

[jrusz]

@jrusz unit tests ^^

Fixed :)