[feat] Enable job account option for the PBS backend

[rsarm]

Closes #1212

[codecov-io]

Codecov Report

Merging #1292 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #1292   +/-   ##
=======================================
  Coverage   91.31%   91.31%           
=======================================
  Files          84       84           
  Lines       12546    12548    +2     
=======================================
+ Hits        11456    11458    +2     
  Misses       1090     1090           

Impacted Files	Coverage Δ
unittests/test_schedulers.py	95.43% <ø> (ø)
reframe/core/schedulers/pbs.py	68.60% <100.00%> (+0.74%)	⬆️

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[ekouts]

lgtm

[vkarak]

It seems you have branched from an older master, therefore the conflicts. Since the unit tests have changed dramatically and you're adding a single line, I'd discourage your from merging and trying to resolve the conflicts. Instead, revert your change in test_schedulers.py, merge with master, then reapply manually your change in the corresponding unit test.

[vkarak]

@rsarm Can you fix this PR as well so that we can merge it?

[vkarak]

Closing this, no more needed due to #1338.