Add context menu and command to show logs

[evidolob]

Resolve: #342

Demo:

Screen.Recording.2021-08-27.at.14.59.55.mov

[codecov-commenter]

Codecov Report

Merging #620 (41c6cba) into master (fb9c474) will decrease coverage by 0.04%.
The diff coverage is 57.14%.

@@            Coverage Diff             @@
##           master     #620      +/-   ##
==========================================
- Coverage   68.38%   68.33%   -0.05%     
==========================================
  Files         114      114              
  Lines        6538     6550      +12     
  Branches     1151     1152       +1     
==========================================
+ Hits         4471     4476       +5     
- Misses       2067     2074       +7     

Impacted Files	Coverage Δ
src/yaml-support/tkn-yaml.ts	92.92% <ø> (ø)
src/pipeline/preview.ts	19.53% <16.66%> (-0.15%)	⬇️
src/pipeline/pipeline-graph.ts	74.82% <63.63%> (-0.70%)	⬇️
src/tekton/taskrun.ts	81.37% <100.00%> (+0.37%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update fb9c474...41c6cba. Read the comment docs.

[mohitsuman]

If possible, we can explore other ways to showcase the Show Logs in the pipeline. Currently it hides in the larger view of the circle. And if there are multiple pipelines added, this can clutter the space.

Need to brainstorm more on the UX side of it.

[mohitsuman]

@evidolob Let's proceed with the current UX and we can make iterations on it in future releases.