4 votesDean Goddard commented
I use VS 2015 Professional and constantly switching between TFS and Git solutions weekly. After deciding long ago to use Araxis as my file comparison / merge tool, I was really surprised when the Git source control in VS didn't support 3rd party compare tools. Not every Git user is cheap and uses freeware. Araxis is well worth the money, and can only hope that VS with Git will one day support it.
We have a lot of investment taking place on our code review platform that will enable iterative code reviews, and we will initially bring that functionality to Git (via pull requests). Improving iterative code reviews for TFVC is still on our backlog, but it is not in our 6 month plan, so we are resetting the status.
216 votesDean Goddard commented
I use Copernic Desktop Search (CDS) or exactly this purpose. While the professional version is cheap, they also have a free version too. Way better then windows search and goolge desktop search. Additionally, you can index emails, office documents, PDFs and others. You do need to add a few extensions like *.cs and *.sql for CDS to support, but once you're setup, it's done.
What you're asking for is a product I believe is outside the scope of Visual Studio.