* Improve typings
Custom API Source allow indexing several types of data. We didn't
account for all of them.
For example, geolocation can be array of arrays of numbers.
This commit improves typings.
The following commits mostly fix TS errors
that appear after this commit.
* Remove type castings to account for all possible variable types
* Update helper functions to accept new CustomAPIFieldValue
* Fix TS error: convert url to string before using it in EuiLink
* Update mock and tests to match updated typings
Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>