Convert axis options from arrays to objects (#6773)

* Convert axis options from arrays to objects

* Updated all chart type defaults
* Throw errors when axis type or position are not specified
* Avoid raising unnecessary errors when merging options into the default configs

* Fix additional tests

* Ensure scale defaults are set if type is not explicitly defined

* Another step

* Include `scale` as `firstIDs.r`

* update docs

* Update for buildOrUpdateScales

* Update migration guide

* Add test back