Closes#11724.
Option is enabled by default for users using qBittorrent's built-in HTTPS capabilities. This flag will never be set if qBittorrent is using plain HTTP.
Users using HTTPS reverse proxies, like "qbt <-> (http) <-> proxy <-> (https) <-> user" should override the flag in the proxy in order to set it, if they wish to do so.
Specifying a height/width value might cut the displayed text or
obstruct centering the text in the button, so let it auto decide
instead.
Closes#11553.
This cleans up the global namespace by explicitly exporting shared values. All html and JavaScript files have been converted to use explicit exports except for client.js and mocha-init.js
