Added numpy and imutils imports to remote_detect()

[cmilanf]

remote_detect() was missing numpy and imutils imports, throwing the following non-critical erros in the log:

ERR zm_detect.py:175 [Error during image grab: name 'np' is not defined]

ERR zm_detect.py:176 [Error during image grab: name 'imutils' is not defined]

This PR fixes the issues by adding the missing imports in zm_detect.py.

[connortechnology]

I believe I moved these because it was very slow to startup for some task that didn't require them. So I moved them down to where they are actually required. Clearly I didn't do a very good job, but I'm loath to just stick them back at the top.

What about if we move remote_detect below main_handler so that by the time it gets called, numpy has been loaded.

[cmilanf]

It may be worth trying:

1. Adding the imports at the begining and measure again performance impact if the last time doing so was with an old Python version. I am currently running ZMES with Python 3.10.
2. Moving remote_detect() is really simple and straight forward, I could try that on my setup.
3. Implement lazy loading for the imports, but that is a Python pending subject.

I can try 2 very easily. For 1, as I am a (happy) remote ML API user, my mesures wouldn't be that useful; and about 3 I wouldn't be keen to add more library dependencies to the code.