Add emoji key to bottom row and option to disable it

java/res/values/attrs.xml

java/res/xml-sw600dp-land/key_space_3kw.xml

java/res/xml-sw600dp/key_space_3kw.xml

java/res/xml-sw600dp/key_space_7kw.xml

java/res/xml-sw600dp/key_styles_common.xml

java/res/xml-sw600dp/row_pcqwerty5.xml

java/res/xml/key_space_5kw.xml

java/res/xml/key_styles_common.xml

java/res/xml/row_pcqwerty5.xml

java/src/org/futo/inputmethod/keyboard/KeyboardId.java

.../src/org/futo/inputmethod/keyboard/KeyboardLayoutSet.java

java/src/org/futo/inputmethod/keyboard/KeyboardSwitcher.java

...g/futo/inputmethod/keyboard/internal/KeyboardBuilder.java

java/src/org/futo/inputmethod/latin/LatinIMELegacy.java

java/src/org/futo/inputmethod/latin/settings/Settings.java

...c/org/futo/inputmethod/latin/settings/SettingsValues.java

...c/org/futo/inputmethod/latin/uix/settings/pages/Typing.kt

...futo/inputmethod/keyboard/KeyboardLayoutSetTestsBase.java