'Remove unnessasary usings' should remove redundant line break when import groups are separated

[Dreamescaper]

Version Used:
VS2019 16.7 P3.1

Steps to Reproduce:
Preconditions: dotnet_separate_import_directive_groups = true

ER:
When using directive groups are separated (with line break), and the whole first group is not used, 'Remove unnessasary usings' should remove all usings from first group, and separating line break as well.

AR:
Line break remains before other usings.