Embed pymysql within the collection and use default test container

This change eliminates the need to install the connector on each
controlled node, as `pymysql` version 1.1.1 is now included. As a
result, we can safely assume its availability, thus simplifying the
testing process.

Also, I managed to remove the need for pre-built test containers. We
now use the default test containers from ansible-test.

plugins/module_utils/pymysql/times.py

@@ -0,0 +1,20 @@
+from time import localtime
+from datetime import date, datetime, time, timedelta
+
+
+Date = date
+Time = time
+TimeDelta = timedelta
+Timestamp = datetime
+
+
+def DateFromTicks(ticks):
+    return date(*localtime(ticks)[:3])
+
+
+def TimeFromTicks(ticks):
+    return time(*localtime(ticks)[3:6])
+
+
+def TimestampFromTicks(ticks):
+    return datetime(*localtime(ticks)[:6])