Slug generation different on CP and Frontend.

Description

Im not sure if it is intended behaviour, I would doubt so, but the algorithm for slug generation on the control panel seems to differ to the createSlug function used in the ElementHelper for frontend requests.

From my understanding the ElementHelper uses the StringHelper to convert the string toKebabCase which uses self::toWords to then will split the string. This is where I believe the differences in the two algorithms occur. The ElementHelper algorithm seems to split the string by CamelCase where as the control panel algorithm does not. You can see the results of this in the steps to reproduce below:

Steps to reproduce

1. In the control panel create a new entry with the title "EntryTest"
2. When entering the title you will see the slug in the right hand side generate to "entrytest"
   http://prntscr.com/n5tg6p
3. Create a new entry with the title "EntryTest" but this time from the frontend by making a request to the actionSaveEntry in the EntriesController.
4. Now on the control panel review the generated slug on the new entry "entry-test"
   http://prntscr.com/n5tk16

Additional info

• Craft version: 3.1.19
• PHP version: 7.2.14
• Database driver & version: MySQL 5.7.25

Start with src/web/assets/cp/src/js/SlugGenerator.js, then compare its behavior with ElementHelper::createSlug in src/helpers/ElementHelper.php and the referenced StringHelper::toWords implementation. Reproduce the "EntryTest" case through the control panel and EntriesController actionSaveEntry; done means both paths generate the same slug.