Simplify query_parameter_as_list

And render the repeated parameter input in the docs.
The first parameter can be a comma-separated list of values

lib/galaxy/webapps/galaxy/api/common.py

@@ -153,7 +153,7 @@ def query_parameter_as_list(query):
 
     Usage example:
     ```python
-        ValueQueryParam: Optional[str] = Query(
+        ValueQueryParam = Query(
             default=None,
             alias="value", # Important! this is the parameter name that will be displayed in the API docs
             title="My Value",
@@ -174,13 +174,12 @@ def query_parameter_as_list(query):
     """
 
     def parse_elements(
-        element: str = query,
-        elements: Optional[List[str]] = Query(default=None, alias=query.alias, include_in_schema=False),
+        elements: Optional[List[str]] = query,
     ) -> Optional[List[Any]]:
-        if query.default != Ellipsis and element is None and not elements:
+        if query.default != Ellipsis and not elements:
             return query.default
-        if elements and len(elements) > 1:
-            return elements
-        return listify(element)
+        if elements and len(elements) == 1:
+            return listify(elements[0])
+        return elements
 
     return parse_elements

lib/galaxy/webapps/galaxy/api/jobs.py

@@ -69,11 +69,11 @@ log = logging.getLogger(__name__)
 router = Router(tags=["jobs"])
 
 
-StateQueryParam: Optional[str] = Query(
+StateQueryParam = Query(
     default=None,
     alias="state",
     title="States",
-    description="Comma-separated list of states to filter job query on. If unspecified, jobs of any state may be returned.",
+    description="A list or comma-separated list of states to filter job query on. If unspecified, jobs of any state may be returned.",
 )
 
 UserDetailsQueryParam: bool = Query(
@@ -95,7 +95,7 @@ ViewQueryParam: JobIndexViewEnum = Query(
 )
 
 
-ToolIdQueryParam: Optional[str] = Query(
+ToolIdQueryParam = Query(
     default=None,
     alias="tool_id",
     title="Tool ID(s)",
@@ -103,7 +103,7 @@ ToolIdQueryParam: Optional[str] = Query(
 )
 
 
-ToolIdLikeQueryParam: Optional[str] = Query(
+ToolIdLikeQueryParam = Query(
     default=None,
     alias="tool_id_like",
     title="Tool ID Pattern(s)",