Ability to install library on all clusters within workspace

[nfx]

There are cases, when a certain set of libraries has to be installed on all of the clusters. One of the ways of doing it is through databricks_global_init_scirpt, though this is more of a workaround. Terraform-friendly solution is to create a data source to return a list of clusters and databricks_cluster_library resource (#904).

data "databricks_clusters" "all" {
}

resource "databricks_library" "cli" {
  for_each = data.databricks_clusters.all.ids
  cluster_id = each.key
  pypi {
    package = "databricks-cli"
  }
}