RFE: Inform when ffmpeg isn't found in the PATH

[sandymac]

RFE: Inform when ffmpeg isn't found in the PATH

Context:

Windows 11, new user, figuring things out.....

GoPro 9 using SD Card in PC

• Camera: GoPro 9
• Operating System: Windows 11
• Version: 1.8

Expected Behavior:

if mmt is missing something, generate error output and fail.

Current Behavior:

mmt shows video files but doesn't make progress copying them. I left it sitting there for tens of minutes wondering what was going on.
mmt would only import jpegs from my GoPro 9

Steps to Reproduce:

Try to use mmt on Windows without ffmpeg installed/added to path