Add course continue button, course progress and pricing table blocks

[seothemes]

Description

Adds:

• Course Continue Button block
• Course Progress block
• Pricing Table block

with Course ID settings allowing blocks to be used on other post types.

How has this been tested?

Manually

Types of changes

Bug fix (non-breaking change which fixes an issue)

Checklist:

• [x] This PR requires and contains at least one changelog file.
• [ ] My code has been tested.
• [ ] My code passes all existing automated tests.
• [x] My code follows the LifterLMS Coding & Documentation Standards.