[Insight] Chain details page

[MicahMaphet]

Added a page with general chain information and a list of blocks with expandable data.
The chain information includes:

• 2 graphs, price over the last 24 hours (same data as the front page) and fee data over the last 128 blocks
• Both graphs have adjustable time scales using the dropdown
• Above both graphs is the amount the fee or price has changed in the time scale

When the rows are expanded, block data excluding transactions is shown

[MichalStachnik]

Looks good, good work!

[kajoseph]

Overall, this looks great! Nice work! I do have a couple of comments:

• The tip has a next block link that throws a nasty uncaught error when clicked. We should at least remove the link...maybe gray out the link arrow and put a tooltip on it.
• The block number blue looks rather dark in dark mode. It's also inconsistent with the blue on the block details/transactions page. We should make these blues consistent between light/dark modes.
• The fee rate data at the top seems odd to me. I don't know that it's particularly helpful to have a diff for the past X blocks. It appears to be essentially a copy n paste from the Exchange Rate graph, but for fee rate data I think it makes more sense to just display as an average across the past X blocks instead of a diff.
• The graphs seem to be off by 1. For example: the 3 hour graph shows 2 hours of data.