WEB_OPTION_EMBED_ENABLED cannot be used because it's a string type

[wkloucek]

Describe the bug

WEB_OPTION_EMBED_ENABLED cannot really be used.
It is a type string to allow an empty default!??

Whenever you set it to true or false, oC Web looks at the /config.json endpoint and sees a string type "true" or "false" and errors because it expects a bool type config option.

Steps to reproduce

1. configure WEB_OPTION_EMBED_ENABLED to any bool-ish string
2. try to load oC Web

Expected behavior

See oC Web being usable and using the configuration from WEB_OPTION_EMBED_ENABLED

Actual behavior

See oC Web failing to load and complaining about the non-bool type config option in the DEV console

Setup

I found that with oCIS 7.0.0-rc.3

cc @kulmann @JammingBen