Imports sorting should be deterministic

[phisco]

We have always been implicitly enforcing a specific sorting for imports, but without the linter actually checking it, many files are adopting different standards.
A pr was merged and got into the latest relese of golangci-lint, reenabling gci autofix. So I suggest enabling gci as a linter and setting any required configuration.

The implicit standard we have been following I think was (standard libraries, everything else, local packages) separated by a line, but feel free to suggest any other standard we should enforce from now on.

[mnencia]

I like the idea. We need to merge #437 before implementing this. Otherwise, it will trigger gosec alerts, as explained in #436.

[mnencia]

This issue on gci would be good to solve before implementing this enhancement daixiang0/gci#65

[armru]

we are waiting for a release that contains daixiang0/gci#88

[mnencia]

It is released and available in the latest golangci-lint version 1.147.3