Provide a way to conveniently vendor chart dependencies into the repo and update dependencies

[distorhead]

Before proceeding

• I didn't find a similar issue

Problem

Current way to vendor deps:

1. Describe dependency in the .helm/Chart.yaml with repository field.
2. Run werf helm dependency update.
3. Unpack downloaded .helm/charts/CHART-VERSION.tgz and remove this tar gz.
4. Comment repository line of target chart.
5. Run werf helm dependency update again.
6. Commit all new and changed files to the git.

Solution (if you have one)

Maybe some special werf dependency update --verdor command which performs steps 2, 3, 4 and 5 automatically.

Additional information

No response