Reference #883: env timeout open k8s logstream

[aeter]

References #883

Adds env variable to configure open logstream timeout.

Please note: when writing this PR: not sure where/how to document the env variable (other than in the code), so users can find it.

Testing:

$ PATH="${PWD}:${PATH}" go test ./pkg/workceptor/kubernetes_test.go
ok      command-line-arguments  0.014s
$ PATH="${PWD}:${PATH}" go test ./pkg/workceptor/kubernetes_test.go -count=1 -race -timeout 5m
ok      command-line-arguments  1.053s 

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[codecov]

Codecov Report

Attention: Patch coverage is 91.66667% with 1 line in your changes missing coverage. Please review.

Project coverage is 43.46%. Comparing base (1be2c55) to head (bb0b10f).
Report is 6 commits behind head on devel.

Files with missing lines	Patch %	Lines
pkg/workceptor/kubernetes.go	91.66%	1 Missing ⚠️

@@            Coverage Diff             @@
##            devel    #1154      +/-   ##
==========================================
+ Coverage   43.26%   43.46%   +0.19%     
==========================================
  Files          33       33              
  Lines        6691     6702      +11     
==========================================
+ Hits         2895     2913      +18     
+ Misses       3552     3546       -6     
+ Partials      244      243       -1     

Files with missing lines	Coverage Δ
pkg/workceptor/kubernetes.go	21.72% <91.66%> (+0.88%)	⬆️

... and 3 files with indirect coverage changes

Components	Coverage Δ
Go	43.46% <91.66%> (+0.19%)	⬆️
Receptorctl	∅ <ø> (∅)