HeliBoard 3.1

Changes since 3.1-beta1:

• block single-letter suggestions from emoji dictonary (seems to be an issue in the native library, they are marked with not_a_word), by @eranl (#1643)
• fix incorrect tab indicator when swiping between emoji categories, by @eranl (#1642, #1645)
• fix language switch button (#1608)
• fix crashes introduced in beta1 (#801, #1614)
• hide debug info for suggestions when suggestions are not shown, by @eranl (#1644)
• hide TLD popup hint in numpad layout (#1640)
• reduce toolbar key size again (#1621)
• minor fixes