mkpkglists improvements

This overlaid MR changes a couple things, namely the format of the meta package archive and only updating archives when needed.

Update When Needed:

We now use the information_schema.tables AUTO_INCREMENT column to keep track of a "serial number" that can be used to tell us whether we need to update or not.

Metadata Format:

    The SQL logic in this file for package metadata now exactly
    reflects RPC's search logic, without searching for specific
    packages.

    Two command line arguments are available:

        --extended | Include License, Keywords and Groups fields

    When one of these arguments are passed, the script will create
    a packages-meta-ext-v1.json.gz, configured via packagesmetaextfile.

    Archive JSON is in the following format: line-separated package objects
    enclosed in a list:

        [
        {...},
        {...},
        {...}
        ]

    This allows users to stream the archive and process packages
    line-by-line, during the local storage process.

    Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/scripts/mkpkglists.py

@@ -15,6 +15,9 @@ userfile = aurweb.config.get('mkpkglists', 'userfile')
 
 
 def should_update(tablename: str) -> int:
+    if aurweb.config.get("database", "backend") != "mysql":
+        return False
+
     conn = aurweb.db.Connection()
 
     db_name = aurweb.config.get("database", "name")