Unify resource files

[tpodolak]

Currently, each analyzer library (C# or VB version) has its own Resources.resx file which contains messages for every diagnostic. As it was noted by @dtchepak
in #14 (comment) in most of the cases, the messages are the same and they only differ in some particular scenarios. Having that in mind we should find a way to share messages across analyzer libraries and override some of them when needed. Thanks to that approach we will avoid message duplication which will make the code-base cleaner and easier to maintain

[dtchepak]

This is excellent 👍