Refine the app developer dashboard

[david-martin]

Follow up on #526
Closes #435

In addition to the changes add in #526, also includes:

• repeating row per API/HTTPRoute
• more compact view of all data already included
• consistent colours for success/error/%
• %ile color gradient
• text box at top to explain dashboard & row repeating
• tooltips updated

[R-Lawton]

Looks great much prefer the more compact design

[thomasmaas]

I know this has already been merged, wondering if for a next iteration it might make sense to combine these boxes in 1 column so you don't get the label duplication. And maybe add a percentage so it's easier to get an idea of the error rate quickly?

total
0,43 r/s (380 r, 100 %)
success
0,43 r/s (321 r, 84 %)
error
0,43 r/s (59 r, 6 %)

[david-martin]

Thanks for the suggestion @thomasmaas.
It would definitely look less cluttered without the title duplication.
We're at the mercy of what you can do with grafana panels, though I do think there's a way to have multiple queries in a single state that appear horizontal or vertical. Could be a way of doing that. Or a table view, though we moved away from that as the single stats allow customisation on the text color.

Would you mind creating a new issue for that if you feel strongly. (There's actually a shortcut to reference your comment in a new issue that I haven't used before. Might be useful)

Thanks