Cuesubmit jobs from config file

[KernAttila]

Link the Issue(s) this Pull Request is related to.
#1275

Summarize your change.

• We are now able to declare jobs from the configuration file (see 1b2b43d)
• We can nest configuration files and use env variables.
• The flag order is respected
• Widgets are constructed according to each flag type:
• The yaml syntax allows solo flags, pycue tokens, mandatory flags, no flags arguments and browsable fileds.
• Invalid text fields are red from the start
• Added some unittests, would love some feedback on those.

Note

• This PR should be merged after :
  • #1280 New widget CueLabelSlider both int and float slider,
  • #1282 Cuesubmit group layout
  • #1283 Cuesubmit Command Feedback

Test
This branch is not testable as is, it depends on previous PRs (new widgets and layout).
All of them have been merged in this one if you want to test it : https://github.com/Wolf-Pipeline/OpenCue/tree/cuesubmit-dev

Question

• Should it replace the hardcoded commands ?
• Are you ok with the commands syntax in the example yaml file ?

Screenshots

[linux-foundation-easycla]

• ✅ login: KernAttila / name: Kern Attila GERMAIN (1b2b43d, d0dc2a1, 76383d8, 4a57c96, 5c2e516, 4f9f747, 691250c, 50810b3, b2df688, 9ec6c19, e2847f4, 1eca853, 4d8e089, 5b00145, 3bbdf53, 20a258a, 5314876, f494104, 65d56b3, 1c70025, e5e2f48, 0d64869, 45c50a1, b5d21c9, df35cbb, edc1fcc, 993666a, b5991f4, 67d88c1, f5f3091, cd60b6e, 4b117a3, d50f7a1, 9d22d01, 8f3b027, 6cfd785, bbaa4a5, 3ed0c0d, f2cbba3)
• ❌ The email address for the commit (5f6a48e, 9e85fe0, fb8c00d) is not linked to the GitHub account, preventing the EasyCLA check. Consult this Help Article and GitHub Help to resolve. (To view the commit's email address, add .patch at the end of this PR page's URL.) For further assistance with EasyCLA, please submit a support request ticket.

[DiegoTavares]

This branch is failing on CLA for some reason. @KernAttila I know it has been a while, but can you try following the CLA process again?