[APM] Use default imports from lodash

[dgieselaar]

Using named imports for lodash includes the whole of Lodash into the bundle. We can try default imports for a smaller bundle.

From:
import { mapValues } from 'lodash'

To:
import mapValues from 'lodash/mapValues'

[elasticmachine]

Pinging @elastic/apm-ui (Team:apm)

[smith]

Since Lodash is now in shared deps, we want to do the opposite. See #78438, #78156, #78100.