Bump send and express in /bundles/org.openhab.ui/web (#2762)

Bumps [send](https://github.com/pillarjs/send) and [express](https://github.com/expressjs/express).
These dependencies needed to be updated together.

Updates `send` from 0.18.0 to 0.19.0
Updates `express` from 4.19.2 to 4.21.0

Signed-off-by: dependabot[bot] <support@github.com>