Feature: #16 - Sanitise version number

[HarryC05]

Description

Fixes #16

This PR replaces the version input control with number controls, and a select control for pre-release titles.

Change Log

• Replaces input control with multiple number controls and a select control
• Removes is pre release meta
• Adds schema to version meta

Steps to test

1. create a new release
2. input the version number
3. publish the release
4. see the correct version number in the admin bar, dashboard widget and on the release notes list

Screenshots/Videos

Screenrecording
http://bigbite.im/v/WfdR9h

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules