[e.cash] Updated high quality Pay2Stay Logo for use-ecash page

Summary: Swapped out a pixelated Pay2Stay.png logo with a high quality image

Test Plan: Visit e.cash/use-ecash and check the Pay2Stay Logo

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D17767