Add ability to modify theme.json's in-game

[LysergikProductions]

Use an inventory gui to give the user the options to click on an existing editable theme, or create a new one from scratch which will be stored in a Map<String, Theme> object.

When creating a new one, refresh the gui with the new blank theme available (all themeIDs are ChatColor.WHITE).
When a gui is selected, bring the user to a new inventory gui with wool block options representing the theme color ids i.e. primary, secondary, etc.

The color of the wool block options will match the current color of that id when the gui is refreshed.

Clicking a color id wool block object will open a third level of inventory gui with dye objects as options for each of the 16 available ChatColor colors. After selecting a dye object, set the theme stored in the Map accordingly and return user to the 2 level gui with the colors ids.

Finally when done, user can click the back option or the finish option.

Finish will send the player a message TextComponent with a clickevent to run an internal command to set the theme in memory. This is used to warn the user that this will overwrite the current custom.json.

After that runs successfully send a confirmation notice to the user in-game and to stdout