Remove System.Net.Http dependency on System.Text.RegularExpressions (dotnet/corefx...

Remove System.Net.Http dependency on System.Text.RegularExpressions (dotnet/corefx#41110)

* Remove System.Net.Http dependency on System.Text.RegularExpressions

This dependency is the only reason we end up with a 105K System.Text.RegularExpressions.dll as part of a trimmed new MVC app.  Regex is used in the case where on Windows a bypass list is provided, in which case each item in the list is changed into a regex, which is then evaluated against each url provided to SocketsHttpHandler.  But the patterns usable are simple: the only special character recognized is an asterisk, which can map to zero or more of any character.  So, we can instead employ a simple processor for such patterns, which then eliminates the need to reference System.Text.RegularExpressions.dll from System.Net.Http.dll.  It also happens to be faster.

* Address PR feedback

* Update src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpWindowsProxy.cs

Co-Authored-By: Jan Kotas <jkotas@microsoft.com>
Commit migrated from https://github.com/dotnet/corefx/commit/0e65e923689962f9634b5948d15f995140cc7c93