Update query editor colorization to match SSMS (#580)

* Ignore editor keyword coloring if keywords are preceded by [ or @

* Force editor text starting with [ or one @ to use plain text styling.

* Add editor syntax check for unicode string literal prefix.

* Add editor syntax category for global system variables.

* Add builtin sql server functions to editor colorization.

* Remove redundant functions in sql syntax list.

* Duplicate editor colorization changes to SQL plist

* Add editor colorization for FULL OUTER JOIN.

* Add some extra missing keywords and functions to editor colorization.

* Make sql function names lower case in syntax-checking regex.

* Change bracketed identifier colorization to include non-word characters.

* Remove unused SQL.plist from sql syntax folder.

* Add yarn.lock files.

extensions/yarn.lock

@@ -315,7 +315,7 @@ dashdash@^1.12.0:
   dependencies:
     assert-plus "^1.0.0"
 
-"dataprotocol-client@file:../dataprotocol-client":
+"dataprotocol-client@file:./../dataprotocol-client":
   version "1.0.0"
   dependencies:
     vscode "1.1.5"
@@ -493,7 +493,7 @@ extend@^3.0.0, extend@~3.0.0, extend@~3.0.1:
 "extensions-modules@file:../extensions-modules":
   version "0.1.0"
   dependencies:
-    dataprotocol-client "file:../../../../Library/Caches/Yarn/v1/dataprotocol-client"
+    dataprotocol-client "file:./../../AppData/Local/Yarn/cache/v1/dataprotocol-client"
     decompress "^4.2.0"
     fs-extra-promise "^1.0.1"
     http-proxy-agent "^2.0.0"