Add Job Viewer visual element to display job details

[Nupoor10]

This PR is regarding issue #412

It includes addition of a new job viewer visual element that is similar to the details panel of the Job Selector visual element

1. Added a new React component JobDetailsViewer
2. Displayed all necessary information outlined in the issue with the correct conditions
3. Added a new method to fetch complete job details
4. Added a new method to check if a job can be cancelled
5. Modified the _GuiCoreLib.py and viselements.json files appropriately

[Nupoor10]

@quest-bot loot #412

[quest-bot]

Quest PR submitted!

@Nupoor10, you are attempting to solve the issue and loot this Quest. Will you be successful?

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Questions? Check out the docs.

[Nupoor10]

I had a few questions regarding this PR.

1. In which subfolder should I add the test file for the JobDetailsViewer component?
2. I tried to implement this component but I get a job_viewer not registered message so how can I implement it?
3. I have implemented the is_cancellable method in job.py folder that returns a boolean value, is that the expected implementation or should it return a ReasonCollection?
4. In the _GuiCoreLib.py file I Have used the __JOB_SELECTOR_ERROR_VAR variable so is it correct?

Additionally if there are any changes do let me know.

[FredLL-Avaiga]

re-use :-)

[FredLL-Avaiga]

Can you not reuse the JobViewer component ?

[FredLL-Avaiga]

1. In which subfolder should I add the test file for the JobDetailsViewer component?

in the same folder, the file name should end with spec.tsx (check ScenarioSelector.spec.tsx)

2. I tried to implement this component but I get a job_viewer not registered message so how can I implement it?

frontend component name is calculated from backend name if not provided
you need to add the react_component parameter to your Element instantiation

3. I have implemented the is_cancellable method in job.py folder that returns a boolean value, is that the expected
   implementation or should it return a ReasonCollection?

a ReasonCollection would be nicer and more consistent

4. In the _GuiCoreLib.py file I Have used the __JOB_SELECTOR_ERROR_VAR variable so is it correct?

No, you need to define a specific error variable name for this new component

PS: please fix the linter errors and update your branch

[FredLL-Avaiga]

Are you still working on this PR @Nupoor10 ?