generate opacity warning for gpu renderer and versions blacklist

[bjlittle]

🚀 Pull Request

Description

This PR allows the ability to generate a text opacity warning which is added to the plotter scene for known troublesome GPU renderer and version combinations.

e.g., the following is generated with the clouds.py example on the Met Office VDI estate, where there are no GPUs and a llvmpipe rasterizer is being used with an older version of OpenGL.

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[codecov]

Codecov Report

Merging #411 (ebad923) into main (7e08f96) will decrease coverage by 0.10%.
The diff coverage is 33.33%.

@@            Coverage Diff             @@
##             main     #411      +/-   ##
==========================================
- Coverage   84.60%   84.51%   -0.10%     
==========================================
  Files          59       59              
  Lines        3242     3248       +6     
==========================================
+ Hits         2743     2745       +2     
- Misses        499      503       +4     

Files Changed	Coverage Δ
src/geovista/common.py	89.33% <33.33%> (-1.27%)	⬇️