feat(manager): support helm values (#5384)

docs/usage/configuration-options.md

lib/config/definitions.ts

lib/manager/common.ts

...ager/helm-requirements/__snapshots__/extract.spec.ts.snap

...nager/helm-requirements/__snapshots__/update.spec.ts.snap

lib/manager/helm-requirements/extract.spec.ts

lib/manager/helm-requirements/update.spec.ts

...r/helm-values/__fixtures__/default_chart_init_values.yaml

...lm-values/__fixtures__/multi_and_nested_image_values.yaml

lib/manager/helm-values/__snapshots__/extract.spec.ts.snap

lib/manager/helm-values/__snapshots__/update.spec.ts.snap

lib/manager/helm-values/extract.spec.ts

lib/manager/helm-values/extract.ts

lib/manager/helm-values/index.ts

lib/manager/helm-values/update.spec.ts

lib/manager/helm-values/update.ts

lib/manager/helm-values/util.ts

renovate-schema.json