Adding support for defining filters on measures (#3624)

* Initial commit

* Using enum for expression and adding to metricsview_aggregation

* Comparison in measure filters

* Adding to metricsview toplist

* Updated proto spec

* Add generic expression syntax

* Final proto draft

* Integrate and test where filter

* Integrate where clause everywhere

* Adding some tests for having clauses

* Add backwards compatibility for filter

* fix lint

* Adding alias support in metricsview_comparison_toplist

* Apply sum() only when having is enabled

* Fix lint

* PR comments

* Move filter helpers to pkg/expressionpb

* refactor filter builder to not use map

* Backwards compatibility for older sort types

* PR comments

* Testing on druid and fixes

* Using outer query

* Removing unused testdata