Add the first version of whoisactive project (#943)

* add the first version of whoisactive

* address comments

* address comments

* fix the issues from the last commit

* clean up package.json

samples/sp_whoIsActive/src/sql/findBlockLeaders.sql

@@ -0,0 +1,6 @@
+IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_NAME = 'sp_WhoIsActive')
+    EXEC sp_WhoIsActive 
+        @find_block_leaders = 1,
+        @get_plans = 1,
+        @sort_order = '[blocked_session_count] DESC'
+GO