Add schema for pagedesigner_condition

Using D11 and having development.services.yml enabled ( config.schema_checker ) cause a warning message like

block.block.mainnavigation:visibility.pagedesigner_condition missing schema.

for each config where this is used.

to fix this following file should be added.

pagedesigner/modules/pagedesigner_block/config/schema/pagedesigner_block.schema.yml

condition.plugin.pagedesigner_condition:
  type: condition.plugin
  label: 'Pagedesigner condition'
  mapping:
    id:
      type: string
      label: 'Condition ID'
    pagedesigner_condition:
      type: integer
      label: 'Hide in pagedesigner'
    negate:
      type: boolean
      label: 'Negate'
    context_mapping:
      type: mapping
      label: 'Context mapping'
      additionalProperties:
        type: string