Input custom Choropleth Legend %value(s), according to chosen number of classes

Problem/Motivation

At the moment the only way to add custom Labels/Values for each Legend class is based on the implementation of
leaflet_choropleth_color_scale_alter hook, defined here:
https://git.drupalcode.org/project/leaflet_choropleth/-/blob/1.0.x/src/P...
and documented in leaflet_choropleth.api.php

To make all this more user friendly, also for (no coders) site builders, we could add a new Leaflet Choropleth settings section specifically focusing on the multivalue text inputs of Legend %value(s), according to the number of classes.

Proposed resolution

Add a new Leaflet Choropleth settings section/element that allows dynamic input of Legend text %value(s).
This new section would be a multivalue texts element that would dynamic (via Ajax) adjust its number of items (granularity) according the chosen Choropleth classification classes.

API changes

Data model changes