Small setting-related fixes

[grorp]

This PR contains some small setting-related fixes:

• It corrects the default value of the fsaa setting in defaultsettings.cpp. The default value of that setting was changed by Add antialiasing filters (FXAA, SSAA) #13253, but the change was only applied to settingtypes.txt.

• It hides the cinematic_camera_smoothing setting on ENABLE_TOUCH builds, as cinematic mode is not available there.

• It makes the mouse_sensitivity setting visible again on ENABLE_TOUCH builds, as it also affects "finger sensitivity":

  https://github.com/minetest/minetest/blob/72ef90885d5030bf6f7f9dd60a475339bde9a929/src/gui/touchscreengui.cpp#L830-L831

To do

This PR is a Ready for Review.

How to test

Look at the settings menu.

[rubenwardy]

It makes the mouse_sensitivity setting visible again on ENABLE_TOUCH builds, as it also affects "finger sensitivity":

This will cause the Keyboard and Mouse page to reappear on Android, containing only the mouse sensitivity setting. Whilst eventually Android will have keyboard and mouse support, we do want this option appear on both pages so it's clear that it applies to touch pad as well. Unfortunately, setting name is a primary key in the new settings GUI which means that whilst a setting can appear multiple times, the definition must be the same.

So either we could make it so the settings GUI supports multiple setting definitions with the same name, or we should split this setting and add "touchscreen_sensitivity" as well.

If we keep with a single setting, a better name would be good

[grorp]

Adding a separate touchscreen_sensitivity setting sounds good.

[grorp]

Updated.

[SmallJoker]

LGTM