Display Block Time on Blocks view

[smcclellan]

Is your feature request related to a problem? Please describe.
I can't tell reading the Blocks view how long each block took. This will give me a sense of how well the chain is performing.

Describe the solution you'd like
Now that we have fast blocks showing on the Explorer, it would help to show the time between blocks more specifically ("Block Time"), in addition to the relative timestamp. The goal is to make it clear how long each block took to produce, e.g. "5 seconds", "20 seconds", etc. I find I'm doing the calculation mentally when I read the relative Timestamp field ("42 seconds ago", "2 mins ago", "10 mins ago", etc.). I could also see this as a toggle-able config.

Additional context
From this image, I can mentally calculate that the recent block times are 11 seconds, 14 seconds, then... it can't be calculated from the data provided: