#2530: Add spotless check for formatting preferences

[hjir]

Check List:

• Fixes Spotless check for formatting preferences #2530
• Unit tests : NA
• Javadoc with a code example (on API only) : NA
• PR meets the contributing guidelines ✅

All the changes relevant to adding the spotless dependency are in the first commit (48a9b14) - I suggest looking at that instead of all the changes that resulted from applying spotless. Apart from adding the spotless dependency and a github workflow, I also added information about spotless to the contributing guidelines.

[hjir]

I will rebase this PR and mark it as ready once #2534 is merged :)

[hjir]

@scordio I picked this up from #2530 but now the pitest pipeline is failing (from what I saw in the logging, there seems to be an OutOfMemoryError). do you have any pointers on what I can do about this?

[scordio]

There is nothing wrong with your changes, it's rather a general problem we have with pitest. Feel free to ignore that failure.

[hjir]

There is nothing wrong with your changes, it's rather a general problem we have with pitest. Feel free to ignore that failure.

alright, thanks! in that case this PR is ready for review :)

[joel-costigliola]

I'm not opposed to applying spotless but I think we need to make the spotless config as close as possible to our existing formatting preferences, there are too many changes in this PR.

[scordio]

Superseded by #3115.