Lizmap must use a semantically correct json

[dmarteau]

What is the bug?

Lizmap and Lizmap plugin produces and consumes a json which is not semantically correct (even if the syntax is ok)

Steps to reproduce the issue

• Generate a Lizmap configuration with the Lizmap plugin.
• Look at entry like: { "toggled": "True" }

Expected behavior

Boolean values should be true or false not "True" or "False"

Environment

• Lizmap version: 3.2+
• QGis version: 3+

This is a problem if one try to parse and use the Lizmap configuration file on a api basis: as most all the languages have modules to handle json correctly, code that manipulate configuration file has to tweak the logic deal with the ambiguity of string value vs boolean value.