Rename `ConfirmationTimeAnchor` to `ConfirmationTimeHeightAnchor`

[danielabrozzoni]

From the ConfirmationTimeAnchor docs:

An Anchor implementation that also records the exact confirmation time and height of the transaction.

If it records both the time and height, why is only "time" included in the name?

[LLFourn]

I guess we felt height was obvious. Maybe not though. Fine with the rename.

[danielabrozzoni]

Reopening as it might have been closed by mistake

[LLFourn]

It was oops.