Refine Fallback Avatars

[lightwalker-eth]

Background Info

We currently display avatars in the following locations:

And please also note the new usage of avatar images on the new Name Detail page being worked on in PR 1024.

For fallback avatar images we are making use of "Boring Avatars" using the marble variant.

Goals

Make our fallback avatar images feel more like "identities". The current swirl gradients don't feel like identities.

Subtasks

• Change from marble variant to beam variant.
• Use the following color scheme which feels more aligned with ENS / ENSAdmin: "#000000", "#ffffff", "#5191c1", "#1e6495", "#0a4b75"