Improve auth token error formatting for easier copy-paste

[jamesbroadhead]

Changes

Format the auth token error message across multiple lines so the
suggested databricks auth login command is on its own line and easy
to copy-paste.

Before:

Error: cache: databricks OAuth is not configured for this host. Try logging in again with `databricks auth login --host https://example.com` before retrying. If this fails, please report this issue to the Databricks CLI maintainers at https://github.com/databricks/cli/issues/new

After:

Error: cache: databricks OAuth is not configured for this host.

To reauthenticate, run the following command:

  $ databricks auth login --host https://example.com

If this fails, please report this issue to the Databricks CLI maintainers at https://github.com/databricks/cli/issues/new

Why

When auth fails, the suggested login command was printed on the same line as the error and config details, making it difficult to select and copy. This follows the same multi-line pattern already used by RewriteAuthError for invalid refresh token errors.

Tests

• Unit tests updated and passing (go test ./cmd/auth/ -run TestToken_loadToken)
• Acceptance test golden file updated and passing (go test ./acceptance/... -run TestAccept/cmd/auth/token)

[github-actions]

An authorized user can trigger integration tests manually by following the instructions below:

Trigger:
go/deco-tests-run/cli

Inputs:

• PR number: 4602
• Commit SHA: 152a1b775d73b42086daf3d4b2f361c84d906f16

Checks will be approved automatically on success.

[andrewnester]

Please include a link to the PR here