Wiki: Non-markdown files with a file extension starting with .md* are shown as wiki pages

Summary

All files ending with .md* are shown as wiki pages.
This includes files with a longer file extension then only .md such as .mdata.
If such a file is attached to a wiki entry, it is automatically added as a separate wiki entry and can be opened by browsing through the wiki pages.

Steps to reproduce

Create a test file and save with any file extension starting with .md, e.g. .mdata or .mdumb and attach this file to a wiki entry such as this:
test.mdumb

What is the current bug behavior?

The test file is shown as a wiki page.

What is the expected correct behavior?

Files with a file extension other then .md should not be shown as markdown wiki pages.

Possible fixes

Only search for explicit .md file extensions.