Give warning when memory usage is set in LSF_RESOURCE

This commit gives the user a deprecationwarning when trying to set
`mem=...` in the `LSF_RESOURCE` resource string. This is preferred to be
set in the new `REALIZATION_MEMORY` option.

Using `REALIZATION_MEMORY` over `LSF_RESOURCE`
* Does not invalidate what we have set as LSF_RESOURCE through the site-config.
* Better handling of memory units (i.e. better UX).
* Makes Ert able to understand the parameter, to be able to compare with actual usage

src/ert/config/parsing/config_schema_deprecations.py

@@ -1,4 +1,5 @@
 from functools import partial
+from typing import List, cast
 
 from .deprecation_info import DeprecationInfo
 
@@ -222,4 +223,11 @@
         "the future. Use REALIZATION_MEMORY instead.",
         check=lambda line: "MEMORY_PER_CPU" in line,
     ),
+    DeprecationInfo(
+        keyword="QUEUE_OPTION",
+        message="Memory requirements in LSF should now be set using REALIZATION_MEMORY and not"
+        " through the LSF_RESOURCE option.",
+        check=lambda line: "LSF_RESOURCE" in line
+        and "mem=" in cast(List[str], line)[-1],
+    ),
 ]