mev-boost metrics

### Problem description

- Right now we don't have a good way to decide a good `min-bid` value for `mev-boosts`
- Also there are 7-10 "no bid received" logs in the last 30 days, this takes up to 20% of mev-boost `"/eth/v1/builder/header` request. This log mostly means there is no bid greater than our `min-bid`
- % of block produced locally panel is not easy to view, if I change the rate_interval to 7d the value is >50% - need to double check

### Solution description

Add metrics to grafana dashboard (may need to enhance lodestar):
- fix % of published local block (see above)
- histogram metrics of block value for both types of blocks
- track all results of `mev-boost` requests. At least we should able to answer how many "getHeader" requests returning no bid ("`no bid received`" log in `mev-boost`)

### Additional context

_No response_