Forumtrack new shortcodes

[rica-carv]

Motivation and Context

New shortcodes to display tracked forum topics data on the user tracked forum topics. Probably this track code can be candidate to use normal shortcodes, since the current hardcoded shortcodes inside the code can't be overriden by theme shortcodes. This pull is just a workaround.

Description

Added LASTPOSTUSERAVATAR, VIEWS and REPLIES shortcodes

How Has This Been Tested?

Tested with e107 v2.3.3

Types of Changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Performance enhancement (non-breaking change which improves efficiency)
• [ ] Code cleanup (non-breaking change which makes code smaller or more readable)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Documentation (a change to man pages or other documentation)

Checklist

• [x] My code adheres to the e107 code style standard.
• [ ] I have read the contributing document.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests pass.