Update OpenToonz to 1.3.0

Summary:
Summarized changelog:

• MyPaint brush for toonz raster levels.
• New option for the output settings: adding Clapperboard.
• New Fx: Text Fx Iwa for rendering text.
• New command: Separate Colors.
• Improved Shift and Trace feature.
• Enabled to convert Toonz 4.x level files (.tzp and .tzu) to TLV via Convert command.
• Enabled to connect multiple nodes at once by Ctrl-dragging in the stage schematic.
• Reverted Alt-dragging feature to the Fx schematic.
• Allowed to use the Duplicate command in the Xsheet.
• Enabled to specify Matte Color for saving transparent raster levels in non-alpha-enabled image format.
• Fixed antialiasing of vector strokes on Linux.
• Improved sound quality for playback and scrubbing on Linux.
• Added Linux desktop data.

Full changelog here.

Packaging changes:

• Removed our desktop file in favour of official one.
• Removed TIFF license from package spec to bring it into line with official appdata.

Test Plan: Created an animation and exported drawn frames to .tiff files.

Reviewers: Triage Team, DataDrake

Reviewed By: Triage Team, DataDrake

Subscribers: DataDrake

Differential Revision: https://dev.getsol.us/D5212