Added some of code on the issue commit and implemented a new views filter...

Added some of code on the issue commit and implemented a new views filter plugin handler to select options.

Closes #3458925

config/schema/views_csv_source.views.schema.yml

+# Schema for the views csv source views plugins.
+
+views.filter.views_csv_source_filter:
+  type: views_filter
+  label: 'CSV Field'
+  mapping:
+    key:
+      type: string
+      label: 'Column name key'
+
+views.filter.views_csv_source_filter_select:
+  type: views_filter
+  label: 'CSV Field'
+  mapping:
+    key:
+      type: string
+      label: 'Column name key'
+    operator:
+      type: string
+      label: 'Operator'
+    value:
+      type: sequence
+      label: 'Values'
+      sequence:
+        type: string
+        label: 'Value'
+    expose:
+      type: mapping
+      label: 'Expose'
+      mapping:
+        reduce:
+          type: boolean
+          label: 'Reduce'
+    group_info:
+      mapping:
+        group_items:
+          sequence:
+            type: views.filter.group_item.in_operator
+            label: 'Group item'
+
+views.query.views_csv_source_query:
+  type: views_query
+  label: 'Views CSV source query'
+  mapping:
+    csv_file:
+      type: string
+      label: 'CSV File'
+    headers:
+      type: string
+      label: 'Headers'
+    request_method:
+      type: string
+      label: 'Request method'
+    request_body:
+      type: string
+      label: 'Request method'
+    show_errors:
+      type: boolean
+      label: 'Show CSV errors'