[packages] Make dummy backend slower

- insert sleeps to make it slower (easier when testing)
- improve debug logging clarity by noting where the messages
  are coming from

src/modules/packages/main.py

@@ -332,19 +332,23 @@ class PMDummy(PackageManager):
     backend = "dummy"
 
     def install(self, pkgs, from_local=False):
-        libcalamares.utils.debug("Installing " + str(pkgs))
+        from time import sleep
+        libcalamares.utils.debug("Dummy backend: Installing " + str(pkgs))
+        sleep(3)
 
     def remove(self, pkgs):
-        libcalamares.utils.debug("Removing " + str(pkgs))
+        from time import sleep
+        libcalamares.utils.debug("Dummy backend: Removing " + str(pkgs))
+        sleep(3)
 
     def update_db(self):
-        libcalamares.utils.debug("Updating DB")
+        libcalamares.utils.debug("Dummy backend: Updating DB")
 
     def update_system(self):
-        libcalamares.utils.debug("Updating System")
+        libcalamares.utils.debug("Dummy backend: Updating System")
 
     def run(self, script):
-        libcalamares.utils.debug("Running script '" + str(script) + "'")
+        libcalamares.utils.debug("Dummy backend: Running script '" + str(script) + "'")
 
 
 class PMPisi(PackageManager):
@@ -502,7 +506,7 @@ def run_operations(pkgman, entry):
             libcalamares.utils.warning("Unknown package-operation key {!s}".format(key))
         completed_packages += len(package_list)
         libcalamares.job.setprogress(completed_packages * 1.0 / total_packages)
-        libcalamares.utils.debug(pretty_name())
+        libcalamares.utils.debug("Pretty name: {!s}, setting progress..".format(pretty_name()))
 
     group_packages = 0
     _change_mode(None)