Refresh sys.path after lib install

[dmohns]

Resolves: #1227, #1221

Scope

This tries to make progress on the error described in #1221

The root cause seems to be that after pip install in a subprocess the module in not added to the "context" in which the script was initially started in. Users hence have to "restart" the script to make the module discoverabled.

I found a way where this restart is no necessary which is essentially a copy from here:

• https://stackoverflow.com/a/24773951
• https://docs.python.org/3/library/site.html

Test Procedure

This is how I tested my changes:

docker build -t local-gateway docker && docker run local-gateway

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