GH3878: Adds support for case sensitive OpenCover filters

[lynkx]

Currently, if you try to apply multiple (case-sensitive) filters (with same-ish values) in your cake script like this:

var coverageInclusionFilters = new List<string>
{
   "+[ModuleName*]*",
   "+[moduleName*]*"
};

var openCoverSettings = new OpenCoverSettings();
//rest of the code omitted for clarity

for(var inclusionFilter in coverageInclusionFilters)
{
   openCoverSettings.WithFilter(inclusionFilter);
}

It produces this kind of a filter argument value:

-filter:"+[ModuleName*]*" 

containing only the first one from the coverageInclusionFilters list from the code above.

As per https://github.com/opencover/opencover/wiki/Usage#understanding-filters
OpenCover filters are case-sensitive.

This change enables you to apply those kind of filter values.

[dnfadmin]

All CLA requirements met.

[lynkx]

cc @DNikolina

[devlead]

LGTM 👍

[devlead]

@lynkx your changes have been merged, thanks for your contribution 👍