fix(slider): correct computing of gapRatio

[Inselhopper]

While the distance between two labels is too short for text at every label, we find out if we use only ticks with no text (gapRatio > 1) and apply text at any other tick (gapRatio = 2), any third tick (gapRatio = 3) and so on

[lubber-de]

🤔 Having your changes applied, the sliders end position value is almost never shown anymore, so people have no idea of the maximum possible value.
Also, the shown value totally differs on different sizes, now.
While this usecase could be of interest for others too, it should need a new setting because of the different behavior.

See the very noticable difference here:

Your changes:
https://jsfiddle.net/lubber/6bzcq2hx/3/

Current FUI
https://jsfiddle.net/lubber/6bzcq2hx/2/

[lubber-de]

See my comment above

[Inselhopper]

The current code is buggy. You can see this if you use a prime number. (webm file) https://jsfiddle.net/inselhopper/uczsp3w6/14/
You wrote: "The slider's end position value is almost never shown anymore" → that is true.
The last label is not shown because of the logic, not because of a bug.
How to fix this? Always showing the last label could lead to overlapping text.
Users could use tooltipConfig to show the last value.

You wrote: "Also, the shown value totally differs on different sizes, now." → it seems like that, but not really.

Current.FUI.-.JSFiddle.-.Code.Playground.1.webm

[Inselhopper]

Question @prudho: since this part of the slider code is mostly yours: can you have a look please at my changes? See #3103

[prudho]

I wrote this code 5 years ago, and barely touched it since... But here's my two cents:
Yes, the actual code is not optimal. Handling some numbers (primes) will not trigger the autogap adjustment. The idea of using the ratio system is nice, but like @lubber-de said, the slider's end position isn't visible some times, and this disturb me. Your solution should be implemented, but only used when specified by a user (so we keep the actual setting by default).