jw.build.cmds: Move build.cmds -> cmds.projects

Reorganize the Python module structure. Placing the command classes
under jw.cmds.projects instead of jw.build.cmds will allow to add a
nested command structure, with the current commands, being mostly
related to building software, found below a "projects" toplevel
command.

Other conceivable commands could be "package" for packaging, or
"distro" for commands wrapping the distribution's package manager.

Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/cmds/projects/CmdPkgProvides.py

@@ -0,0 +1,10 @@
+# -*- coding: utf-8 -*-
+
+from argparse import Namespace, ArgumentParser
+
+from .BaseCmdPkgRelations import BaseCmdPkgRelations as Base
+
+class CmdPkgProvides(Base): # export
+
+    def __init__(self) -> None:
+        super().__init__('provides', help='Print packages and capabilities provided by a given package')