Bump to v2.3.0, "stable"

Bump version to 'v2.3.0-preview.4

Touch-up changelog

[Ignore] rev to 2.3.0-preview.1 (PowerShell#1360)

Added Handler for Semantic Tokenization (PowerShell#1328)

* added basic semantic token support

* removed unnecessary imports

* removed unnecessary field

* minor refactoring changes

* minor refactoring changes

* change tokenize to non async

* rename handler

* refactoring + copyright

* renamed handler file

* Delete log20200713.txt

* moved/refactored handler

* added e2e tets

* updated test

* remove pragma

* removed extra spacing

* added testing for converting from PS token to semantic tokens

* refactored the functions related to converting between tokens

* refactored ConvertSemanticToken

* fixed tests

* added more test cases

* fixed spacing

* added enum test

* fixed spacing issues

* fixed spacing, added note about token array representation

* changed name to PsesSemanticTokensHandler

* reformatted fields

* renamed file

* used Assert.Collection instead of Assert.Single

* modified yml file to fix build

* undo changes in yml file

* addressed issues in PR

* added basic semantic token support

* removed unnecessary imports

* removed unnecessary field

* minor refactoring changes

* minor refactoring changes

* change tokenize to non async

* rename handler

* refactoring + copyright

* renamed handler file

* moved/refactored handler

* added e2e tets

* Delete log20200713.txt

* updated test

* remove pragma

* removed extra spacing

* added testing for converting from PS token to semantic tokens

* refactored the functions related to converting between tokens

* refactored ConvertSemanticToken

* fixed tests

* added more test cases

* fixed spacing

* added enum test

* fixed spacing issues

* fixed spacing, added note about token array representation

* changed name to PsesSemanticTokensHandler

* reformatted fields

* renamed file

* used Assert.Collection instead of Assert.Single

* addressed issues in PR

* remove unused using

* Delete Untitled-1.json

Co-authored-by: Justin Chen <t-chenju@microsoft.com>

Rev version to 2.3.0-preview.1 and update CL (PowerShell#1310)

rev version to 2.2.0-preview.4 update CL (PowerShell#1305)

Rev version to 2.2.0-preview.3 and update CL (PowerShell#1303)

[Ignore] update CL

cl for v2.2.0-preview.1 (PowerShell#1275)