Implement genre

[michaelarnauts]

This PR implements genre in the EPG. The sting will be passed as it is received from the Add-on. There is no color coding done yet.

Related PR's:

• https://github.com/add-ons/plugin.video.viervijfzes/pull/31
• https://github.com/add-ons/plugin.video.vtm.go/pull/186
• https://github.com/add-ons/plugin.video.vrt.nu/pull/776

Fixes #30