refactoring: trying to remove all the css overrides in history tab and make the styles more more inline with best practice css, and if needed use modifier overrides instead

refactoring: moved compare dashboard version command out of sqlstore, the code in this command did not use any sql operations and was more high level, could be moved out and use existing queries to get the versions

refactoring: moved dashboard history item formating (message) and fixed dashboard history migration issue, and removed from frontend tests that where no longer needed

operations instead of duplicating a bunch of get & save logic.

refactoring: Renamed dashboard version queries that wrongly had Command suffix, added missing OrgId to dashboard history commands and queries

* Update to latest oauth2 library using govendor

* Follow API changes

I added in a description since there was just TODO there originally.

chrome: an attempt to fix scroll issue with chrome, but this did not fix the problem as it seems to be caused by some interaction between graph rendering and scrolling, #8494

* remove X-Forwarded-* headers added by nginx when proxying data source & plugin requests

* properly handle X-Forwarded-For

fixes #8446. Data with all values equal to zero, creates a max with the
value of Infinite. The for loop for creating ticks then gets stuck in an
infinite loop. This fix resets min and max and creates some fake ticks
for the y-axis if the min and max are not finite numbers.

Resolves issue #8467