[User] Canvas UI improvements

[James-Firth]

• Size
• Fish move 🐟 🐠
• Ocean waves (static and then moving) 🌊
• Boats ⛵

See #155 for a sketch

[normful]

Now that we've increased the relative size of the fisher table, in comparison to the ocean canvas, such that the ocean is relatively tiny for some resolutions (e.g. 1024 x 768), do you guys think it's even worth it to implement these animations? They'll be so tiny!

[jorgearanda]

They are tiny indeed! No, not needed for now. Once the current UI is settled I'll get feedback again and we'll see if this would be welcome.