fix: support array of 1 for query parameter arrays (round 2) (#225)

#220 got a bit off-track with scope creep.

this PR takes a similar approach, but for internal use only
- detects query parameters with array type schemas
- adds an internal annotation to indicate these need preprocessing
- applies a `z.preprocess` to coerce an individual value to an array of
1 element, before parsing with the array schema
- for `joi` we resort to a pretty hacky wrapping of the schema with a
object that does the preprocessing, as the `joi` extension API didn't
work as I'd expected it to.

will continue experimenting with making this a more generally useful
feature for handling things like parsing `date-time` strings to be a
`Date`, etc, separately.

fixes #217 

**Testing Notes**
Need to improve automated test coverage still, but manually tested on a
running server:
- No query params
- 1 element
- 2 elements
- 2 elements, 1 element

and it seems to be working correctly.

```
listening on http://127.0.0.1:3000
query { query: {} }
query { query: { statuses: [ 'complete' ] } }
query { query: { statuses: [ 'complete', 'incomplete' ] } }
query { query: { statuses: [ 'complete', 'incomplete' ] } }
query { query: { statuses: [ 'complete', 'incomplete' ], tags: [ '123' ] } }
```

integration-tests-definitions/todo-lists.yaml

@@ -10,13 +10,17 @@ paths:
         schema:
           type: string
           format: date-time
-      - name: status
+      - name: statuses
         in: query
         schema:
-          type: string
-          enum:
-            - incomplete
-            - complete
+          $ref: '#/components/schemas/Statuses'
+      - name: tags
+        in: query
+        schema:
+          type: array
+          items:
+            type:
+              string
     get:
       operationId: getTodoLists
       responses:
@@ -174,7 +178,13 @@ components:
         updated:
           type: string
           format: date-time
-
+    Statuses:
+      type: array
+      items:
+        type: string
+        enum:
+          - incomplete
+          - complete
   parameters:
     listId:
       name: listId