[FIX] website: allow step to fill more than 9/12 of the page width

Prior to this commit, the steps block options could not support a column
that was more than nine out of twelve (bootstrap columns) wide.

Steps to reproduce the bug:
- Drop a block step on a page
- Set a width of 10 columns on the first step
- Set a width <= 2 columns on the second step

=> the connector is not well displayed.

task-3033126

closes odoo/odoo#108362

X-original-commit: 9c4e0eaa60ad89140661e3c297ea1b4e22d6faae
Signed-off-by: Benoit Socias (bso) <bso@odoo.com>

addons/website/static/src/snippets/s_process_steps/options.js

@@ -135,8 +135,9 @@ options.registry.StepsConnector = options.Class.extend({
      * @returns {integer}
      */
     _getStepColSize(stepEl) {
-        const colClass = stepEl.className.split(' ').find(cl => cl.startsWith('col-lg'));
-        return parseInt(colClass[colClass.length - 1]);
+        const classPrefix = 'col-lg-';
+        const colClass = stepEl.className.split(' ').find(cl => cl.startsWith(classPrefix));
+        return parseInt(colClass.replace(classPrefix, ''));
     },
     /**
      * Returns the padding of the step, as a number of bootstrap lg-col.
@@ -146,8 +147,10 @@ options.registry.StepsConnector = options.Class.extend({
      * @returns {integer}
      */
     _getStepColPadding(stepEl) {
-        const paddingClass = stepEl.className.split(' ').find(cl => cl.startsWith('offset-lg'));
-        return paddingClass ? parseInt(paddingClass[paddingClass.length - 1]) : 0;
+        const classPrefix = 'offset-lg-';
+        const paddingClass = stepEl.className.split(' ').find(cl => cl.startsWith(classPrefix));
+        return paddingClass ? parseInt(paddingClass.replace(classPrefix, '')) : 0;
+
     },
     /**
      * Returns the svg path based on the type of connector.