Rename Pleroma.Mix.Tasks.Common -> Mix.Pleroma and import it's functions

instead of aliasing

This seems to be the convention for functions that can be reused between
different mix tasks in all Elixir projects I've seen and it gets rid on
an error message when someone runs mix pleroma.common

Also in this commit by accident:
- Move benchmark task under a proper namespace
- Insert a space after the prompt

lib/mix/tasks/pleroma/instance.ex

@@ -4,7 +4,7 @@
 
 defmodule Mix.Tasks.Pleroma.Instance do
   use Mix.Task
-  alias Mix.Tasks.Pleroma.Common
+  import Mix.Pleroma
 
   @shortdoc "Manages Pleroma instance"
   @moduledoc """
@@ -70,7 +70,7 @@ defmodule Mix.Tasks.Pleroma.Instance do
     if proceed? do
       [domain, port | _] =
         String.split(
-          Common.get_option(
+          get_option(
             options,
             :domain,
             "What domain will your instance use? (e.g pleroma.soykaf.com)"
@@ -79,16 +79,16 @@ defmodule Mix.Tasks.Pleroma.Instance do
         ) ++ [443]
 
       name =
-        Common.get_option(
+        get_option(
           options,
           :instance_name,
           "What is the name of your instance? (e.g. Pleroma/Soykaf)"
         )
 
-      email = Common.get_option(options, :admin_email, "What is your admin email address?")
+      email = get_option(options, :admin_email, "What is your admin email address?")
 
       notify_email =
-        Common.get_option(
+        get_option(
           options,
           :notify_email,
           "What email address do you want to use for sending email notifications?",
@@ -96,7 +96,7 @@ defmodule Mix.Tasks.Pleroma.Instance do
         )
 
       indexable =
-        Common.get_option(
+        get_option(
           options,
           :indexable,
           "Do you want search engines to index your site? (y/n)",
@@ -104,21 +104,19 @@ defmodule Mix.Tasks.Pleroma.Instance do
         ) === "y"
 
       db_configurable? =
-        Common.get_option(
+        get_option(
           options,
           :db_configurable,
           "Do you want to be able to configure instance from admin part? (y/n)",
           "y"
         ) === "y"
 
-      dbhost =
-        Common.get_option(options, :dbhost, "What is the hostname of your database?", "localhost")
+      dbhost = get_option(options, :dbhost, "What is the hostname of your database?", "localhost")
 
-      dbname =
-        Common.get_option(options, :dbname, "What is the name of your database?", "pleroma_dev")
+      dbname = get_option(options, :dbname, "What is the name of your database?", "pleroma_dev")
 
       dbuser =
-        Common.get_option(
+        get_option(
           options,
           :dbuser,
           "What is the user used to connect to your database?",
@@ -126,7 +124,7 @@ defmodule Mix.Tasks.Pleroma.Instance do
         )
 
       dbpass =
-        Common.get_option(
+        get_option(
           options,
           :dbpass,
           "What is the password used to connect to your database?",
@@ -166,31 +164,31 @@ defmodule Mix.Tasks.Pleroma.Instance do
           dbpass: dbpass
         )
 
-      Common.shell_info(
+      shell_info(
         "Writing config to #{config_path}. You should rename it to config/prod.secret.exs or config/dev.secret.exs."
       )
 
       File.write(config_path, result_config)
-      Common.shell_info("Writing #{psql_path}.")
+      shell_info("Writing #{psql_path}.")
       File.write(psql_path, result_psql)
 
       write_robots_txt(indexable)
 
-      Common.shell_info(
+      shell_info(
         "\n" <>
           """
           To get started:
           1. Verify the contents of the generated files.
-          2. Run `sudo -u postgres psql -f #{Common.escape_sh_path(psql_path)}`.
+          2. Run `sudo -u postgres psql -f #{escape_sh_path(psql_path)}`.
           """ <>
           if config_path in ["config/dev.secret.exs", "config/prod.secret.exs"] do
             ""
           else
-            "3. Run `mv #{Common.escape_sh_path(config_path)} 'config/prod.secret.exs'`."
+            "3. Run `mv #{escape_sh_path(config_path)} 'config/prod.secret.exs'`."
           end
       )
     else
-      Common.shell_error(
+      shell_error(
         "The task would have overwritten the following files:\n" <>
           (Enum.map(paths, &"- #{&1}\n") |> Enum.join("")) <>
           "Rerun with `--force` to overwrite them."
@@ -215,10 +213,10 @@ defmodule Mix.Tasks.Pleroma.Instance do
 
     if File.exists?(robots_txt_path) do
       File.cp!(robots_txt_path, "#{robots_txt_path}.bak")
-      Common.shell_info("Backing up existing robots.txt to #{robots_txt_path}.bak")
+      shell_info("Backing up existing robots.txt to #{robots_txt_path}.bak")
     end
 
     File.write(robots_txt_path, robots_txt)
-    Common.shell_info("Writing #{robots_txt_path}.")
+    shell_info("Writing #{robots_txt_path}.")
   end
 end