v1.2.0

Changes & fixes:

• Completely new tweening system that avoids coroutines completely, improving performance immensely.
• Changed the pause handling logic, also removing Playing value, as now it uses the Paused value to check for the playback state.
• Updated Signal+ to v2.7.0.
• Changed error message 'level' to 2 for easier debugging.
• Internal tween type for type checking inside the module itself.
• Moved hardcoded default repeat count to a variable.
• Moved if statements for returns in easing functions into one return statement.
• Switched class names to PascalCase.
• Comment changes and additions.
• Spacing and order changes.