## Problem
`coder exp sync want` and `coder exp sync start` both printed generic
success messages, which hid the dependency units involved in startup
coordination.

Before, declaring dependencies with `sync want` printed:

```text
Success
```

Before, `sync start` printed while waiting, then finished with another
generic success message:

```text
Waiting for dependencies of unit 'test-unit' to be satisfied...
Success
```

## Solution
Print the dependency units in both cases, using wording that matches
where the command is in the lifecycle.

After, `sync want` prints the dependencies it declared for the unit:

```text
Unit "test-unit" declared dependencies: [dep-unit]
```

After, `sync start` enumerates the dependencies while it is waiting,
then prints the same dependencies after the unit starts executing:

```text
Unit "test-unit" is waiting for dependencies to be satisfied: [dep-unit, dep-unit-2]
Unit "test-unit" finished waiting for dependencies: [dep-unit, dep-unit-2]
```

The sync golden tests now cover the updated output, including multiple
dependencies for `sync start`.

(cherry picked from commit f3e90b3)