With `RunWithSuggestedFixes` we can assert that the output of the
diagnostics created are corect. It's a bit weird because the golden file
will contain all the expected assertions even though the would no longer
be triggered. For now they're kept to make the test pass.

Ref: https://godocs.io/golang.org/x/tools/go/analysis/analysistest#RunWithSuggestedFixes

We can now fix a line that's not the one we reported. This is used when
we have multiple cuddled vars but want to keep the last one since it's
allowed (and required if error cuddling is forced).

Also adds all the config flags

We currently only support adding a newline if we don't think vars should
be cuddled. For `var` blocks we would ideally group them instead of
separating by newline but this is currently not supported.

This test only serves as an expectation of the fixer.

* Remove newline in end of block
* Remove newline in start of block (and comments...)

This is WIP because we need to preserve the comments so they don't get
deleted when we remove beginning of blocks.

* Work around case blocks
* All tests now uses fixer
* Different tests can set config per test