Doc 2646 streams tutorial code examples in C# (#272)

* DOC_2646 Added stream code samples

* DOC-2646 Fixed minor issues

* DOC-2646 Fixed array initialisers

* DOC-2646 dotnet format changes

* DOC-2646 added version check for feature

* DOC-2646 dotnet format changes

* DOC-2646 version check fix

* DOC-2646 removed unused using statements

* DOC-2646 made string function static

* DOC-2646 try to fix undefined attribute error

* DOC-2646 changed doc test namespace

* DOC-2646 replace custom string formatting functions

* DOC-2646 dotnet format

* change class name to StreamTutorial

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Co-authored-by: shacharPash <[email protected]>

Author: andy-stark-redis