Update codebase to use Array.Empty<T>

[mjedrzejek]

Update codebase to use Array.Empty

Fixes #4051

[dnfadmin]

All CLA requirements met.

[manfred-brands]

This is only a subset of the zero element array allocations.
There are many more.
You can find them with a regular expression: new [a-zA-Z_0-9]*\[0\]

[mjedrzejek]

@manfred-brands thanks!
I used the regular expression and added more changes to the MR. I was not able to replace 5 occurrences where empty array is created as a parameter for attribute - if I try to change the code there, I am getting a compiler error and I was not able to find a workaround (error: CS0182 -
An attribute argument must be a constant expression, typeof expression or array creation expression of an attribute parameter type).

[manfred-brands]

Technically the conversion are done correctly.
Looking at the code, two of them should actually be Enumerable.Empty<int>().
Please update those two please.

[manfred-brands]

For next time, note that there is a 'Quickfix' for CA1825, that does the simple conversion for you.
It also knows that you cannot convert the ones in attributes.

Go to one place where there was an empty array allocation and select Ctrl+. or select the lightbulb.

Unfortunately that quickfix doesn't add using statements, nor does the Enumerable.Empty conversion.

[mikkelbu]

LGTM. Thanks for the work @mjedrzejek 👍

I've updated the first message in this PR, so that it will close #4051