[Cashtab] Remove titles from send.svg & cog.svg

Summary: Related to task T2356. The settings cog and send icon had tooltip popups of their titles, despite the rest of the icons not having tooltips on hover. Removed the titles from send.svg and cog.svg to create uniformity across all icons.

Test Plan:
cd web/cashtab && npm start
hover over the Send icon in the navbar, observe the lack of tooltip
hover over the Cog icon in the navbar, observe the lack of tooltip.

Reviewers: bytesofman, #bitcoin_abc

Reviewed By: bytesofman, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D11284