xray cleanup (#5880)

* Add :largest-contributors to comparison, bug fixes, refactoring

* Add valid-pairs and field endpoints to comparisons

* Dampen field difference weight in contribution assesment

* fix nice-bins for empty histogram

* fix for nice-bins for histogram with only 1 value

* Change comparison field zoom in. Rename largest-contributor to top-contributor

* fix halfassed rename

* refactor + new components

* use true multiseries

* cleanup

* include constituents in card

* add dataset to card return

* card wip

* growth rate

* check for values

* lint

* cardify all series features. Unpack linear regression

* add linear regression

* use percentages

* flip order

* add growth series description

* add additional info

* fix layout

* layout tweaks

* add action in qb

* show growth series as a %

* xray segment action

* flow

* Support all time breakdowns, fix filtering bug

* make linter happy

* more robust test

* Add conditional descriptions for growth-series. Update tests.

* add periodicity to cards

* Update for updated distance measure

* Removed updates to comparison as they should not be part of PR

* Correct chi^2 distance

* fix headings

* fix flow

* disable flow for action

* use beaker for xray actions

* move specs to proper test directory

* Fix round-to-month when crossing year

* add key

* Add smoke tests for table xray and segment xray pages

* Correctly handle unixtimestamps encoded as bigints

* Add test cases for question xray page and segment xray query builder action

* Test also timeseries question action widget action

* Fix lint errors for xray tests

* Fix Histogram element passing data in invalid format to Visualization

* Fix integration tests for xrays

* Make xrays urls in services.js consistent with other urls

* fix periodicty reweighing

* add sample? predicate

* cleanup

* spacing

* cleanup

* fix failing tests

* fix failing tests

* Update tests

* Refactored periodicity reweighing, more tests

* Support :as in date-time fields, more tests, fix another periodicity bug

* add error handling

* add missing label

* tweak fidelity icon size

* fix histograms

* more specific legend hiding

* hide link for now

* card xray title

* fix field header

* fix stat group padding

* card error handling

* remove duplicated code