For https://github.com/turt2live/matrix-media-repo/issues/445

For investigating https://github.com/turt2live/matrix-media-repo/issues/448

Fixes https://github.com/turt2live/matrix-media-repo/issues/340

This code path is *definitely* called.

For https://github.com/turt2live/matrix-media-repo/issues/448

For https://github.com/turt2live/matrix-media-repo/issues/451

Fixes https://github.com/turt2live/matrix-media-repo/issues/443

Fixes https://github.com/turt2live/matrix-media-repo/issues/444

Also fixes a memory issue where we'd decode the entire image before deciding that the image is too small for thumbnailing.

For https://github.com/turt2live/matrix-media-repo/issues/450

For https://github.com/turt2live/matrix-media-repo/issues/450

This reverts commit 73dfdc84.

Support MSC4040 SRV records

Fixes https://github.com/turt2live/matrix-media-repo/issues/439

They might have already run migration 19 from 8d05c654

Fixes https://github.com/turt2live/matrix-media-repo/issues/426