Ability to set integer values beyond Linear/Log/Sqrt scales

[rshen91]

Is your feature request related to a problem? Please describe.
This issue expands on #389 which only addressed integersOnly for Linear/Log/Sqrt scales. This issue is to address applying the same principle also on the X scale.

The minInterval is always computed on the xScale as the minimum difference between consecutive values in the dataset, and it's never computed on the yScale(default to 0).

Kibana Cross Issues

• Add log scale in charts for x-axis kibana#4530
• [TSVB] Ability to set Y-axis to integer value kibana#28614

Checklist

• this request is checked against already exist requests
• every related Kibana issue is listed under Kibana Cross Issues list
• kibana cross issue tag is associated to the issue if any kibana cross issue is present