Misleading transaction time when in micro block

[friedger]

Describe the bug A time in the past is shown for transactions in micro blocks

The time does not makes sense as it looks like that the tx is executed at the already confirmed block, more precisely, that the clarity variable block_height is the height of the confirmed block. This is not true.

To Reproduce Steps to reproduce the behavior:

1. Go to https://explorer.stacks.co/transactions?chain=testnet
2. See timestamp on microblock

Expected behavior Do not show a transaction time until the block with the block_height used during processing the transaction is confirmed on Bitcoin.

Screenshots