fix(client): Fix "acq" command group

There are only three commands here now:

- list: to list acquisition
- files: to list acquisition files
- show: to show an acquisition

The "where" command is now handled by "show":
```
  alpenhorn acq show ACQNAME --show-nodes
```

The "syncable" command will be re-implemented as part of the
"syncable" command in the "file" command group, where an acq-name
limit can be specified.  Something like:
```
  alpenhorn file syncable --acq=ACQ
```

alpenhorn/client/acq/__init__.py

@@ -0,0 +1,20 @@
+"""Alpenhorn client interface for operations on `ArchiveAcq`s."""
+
+import re
+import sys
+import click
+import peewee as pw
+
+from .files import files
+from .list import list_
+from .show import show
+
+
+@click.group(context_settings={"help_option_names": ["-h", "--help"]})
+def cli():
+    """Manage Acquisitions."""
+
+
+cli.add_command(files, "files")
+cli.add_command(list_, "list")
+cli.add_command(show, "show")

alpenhorn/client/acq/files.py

@@ -0,0 +1,111 @@
+"""alpenhorn acq files command."""
+
+import click
+import peewee as pw
+from tabulate import tabulate
+
+from ...common.util import pretty_bytes
+from ...db import ArchiveAcq, ArchiveFile, ArchiveFileCopy, StorageGroup, StorageNode
+from ..cli import echo
+from ..options import client_option, not_both
+
+
+@click.command()
+@click.argument("acq", metavar="ACQ")
+@client_option("group")
+@client_option("node")
+@click.option(
+    "--show-removed",
+    is_flag=True,
+    help="If used with --node or --group, also list files that have been removed from the node/group.",
+)
+def files(acq, group, node, show_removed):
+    """List files in an Acqusition.
+
+    Lists files in the Acqusition named ACQ."""
+
+    not_both(node, "node", group, "group")
+
+    try:
+        acq = ArchiveAcq.get(name=acq)
+    except pw.DoesNotExist:
+        raise click.ClickException("No such Acquisition: " + acq)
+
+    data = []
+    if node:
+        headers = ["Name", "Size", "Node State", "Size on Node", "MD5"]
+
+        try:
+            node = StorageNode.get(name=node)
+        except pw.DoesNotExist:
+            raise click.ClickException("No such Storage Node: " + node)
+        query = (
+            ArchiveFileCopy.select()
+            .join(ArchiveFile)
+            .where(ArchiveFile.acq == acq, ArchiveFileCopy.node == node)
+        )
+
+        for copy in query:
+            state = copy.state
+            if show_removed or state != "Removed":
+                file_size = (
+                    "-" if copy.file.size_b is None else pretty_bytes(copy.file.size_b)
+                )
+                node_size = pretty_bytes(copy.size_b) if copy.size_b else "-"
+                data.append(
+                    (
+                        copy.file.name,
+                        file_size,
+                        state,
+                        node_size,
+                        copy.file.md5sum,
+                    )
+                )
+    elif group:
+        headers = ["Name", "Size", "Group State", "MD5"]
+
+        try:
+            group = StorageGroup.get(name=group)
+        except pw.DoesNotExist:
+            raise click.ClickException("No such Storage Group: " + group)
+        query = (
+            ArchiveFileCopy.select()
+            .join(ArchiveFile)
+            .switch(ArchiveFileCopy)
+            .join(StorageNode)
+            .where(ArchiveFile.acq == acq, StorageNode.group == group)
+            .group_by(ArchiveFile.id)
+        )
+
+        for copy in query:
+            state = group.filecopy_state(copy.file)
+
+            if show_removed or state != "N":
+                # Convert state to words
+                if state == "Y":
+                    state = "Present"
+                elif state == "M":
+                    state = "Needs Check"
+                elif state == "N":
+                    state = "Removed"
+                else:
+                    state = "Corrupt"
+
+                file_size = (
+                    "-" if copy.file.size_b is None else pretty_bytes(copy.file.size_b)
+                )
+
+                data.append((copy.file.name, file_size, state, copy.file.md5sum))
+    else:
+        headers = ["Name", "Size", "MD5"]
+
+        query = ArchiveFile.select().where(ArchiveFile.acq == acq)
+
+        for file in query:
+            file_size = "-" if file.size_b is None else pretty_bytes(file.size_b)
+            data.append((file.name, file_size, file.md5sum))
+
+    if data:
+        echo(tabulate(data, headers=headers))
+    else:
+        echo("No files.")