Remove the all_urls optional permission

[micz]

Remove the all_urls optional permission and use the specific url defined by the user in the OpenAI Compatible API options. This modification has been asked by the Thunderbird Addons Reviewer.

For more info see here: https://thunderbird.topicbox.com/groups/addons/Tafa58394231a18f8-M3e565a75287313ea4395ff5f/prefer-to-use-optionalhostpermissions-to-get-around-cors-issues-with-fetch

For this the minimun supported version is 140, check the usage stats to define if older versions are still used and if we need to change the behaviour to support also older versions.