Fills missing datapoints with 0s so that all metrics chart lines have data for all datapoints. Closes # [1-2278](https://linear.app/unleash/issue/1-2278/fill-the-metrics-data-with-0s-when-not-enough-data-to-fill-the-chart) Before: <img width="1547" alt="Screenshot 2024-04-10 at 12 48 22" src="https://github.com/Unleash/unleash/assets/104830839/35885852-d986-4760-84e2-9e8ef61bedf0"> <img width="1550" alt="Screenshot 2024-04-10 at 12 48 44" src="https://github.com/Unleash/unleash/assets/104830839/3385b8eb-08e2-4cc9-86b2-7b31b9fe81ef"> After: <img width="1582" alt="Screenshot 2024-04-10 at 13 43 10" src="https://github.com/Unleash/unleash/assets/104830839/d3713df3-869b-48ba-b2ab-095027b37506"> <img width="1545" alt="Screenshot 2024-04-10 at 13 42 49" src="https://github.com/Unleash/unleash/assets/104830839/44a6e662-2e9f-4fe8-8299-c15ab8f8e261"> --------- Signed-off-by: andreas-unleash <andreas@getunleash.ai>
