Provide a non-translatable alternative to "text" and "text_format" schema types

Problem/Motivation

There doesn't seem to be a non-translatable alternative to "text" and "text_format" in the configuration schema.
Overriding the "translatable" value for type: text or type: text_format isn't possible.

Steps to reproduce

If you need a schema with a multiline string (or even a WYSIWYG input) that is not translatable, there doesn't seem to be such a type available in core?

See the following example:

example.settings:
  type: config_object
  label: 'Example schema.yml with a multiline text that should not be translatable'
  mapping:
  copyrights:
      type: mapping
      label: 'Copyrights'
      # Copyrights should be kept in sync across all languages (=not translatable).
      translatable: false
      mapping:
        value:
          type: text
          label: 'Text'
          # Copyrights should be kept in sync across all languages (=not translatable).
          translatable: false
        format:
          type: string
          label: 'Text format'

text is defined as follows in core/config/schema/core.data_types.schema.yml

# Human readable string that can contain multiple lines of text or HTML.
text:
  type: string
  label: 'Text'
  translatable: true
  constraints:
    Regex:
      # Disallow all control characters except for tabs (ASCII 9, 0x09) as well
      # as carriage returns (ASCII 13, 0x0D) and line feeds (ASCII 10, 0x0A),
      # which are used for line endings:
      # - Windows: `\r\n`
      # - old macOS: `\r`
      # - *nix: `\n`
      # @see https://stackoverflow.com/a/66587087
      pattern: '/([^\PC\x09\x0a\x0d])/u'
      match: false
      message: 'Text is not allowed to contain control characters, only visible characters.'

text_format is defined as follows in core/config/schema/core.data_types.schema.yml

# Text with a text format.
text_format:
  type: mapping
  label: 'Text with text format'
  # We declare the entire mapping of text and text format as translatable. This
  # causes the entire mapping to be saved to the language overrides of the
  # configuration. Storing only the (to be formatted) text could result in
  # security problems in case the text format of the source text is changed.
  translatable: true
  mapping:
    value:
      type: text
      label: 'Text'
      # Mark the actual text as translatable (in addition to the entire mapping
      # being marked as translatable) so that shipped configuration with
      # formatted text can participate in the string translation system.
      translatable: true
    format:
      type: string
      label: 'Text format'
      # The text format should not be translated as part of the string
      # translation system, so this is not marked as translatable.

Proposed resolution

It would me good to either have untranslated alternatives to

• text
• text_format

Or have the ability to override their translatability with
translatable: false for such cases, which is at least complictated or even impossible for text_format due to the several levels.

My current workaround is for now:

example.settings:
  type: config_object
  label: 'Example schema.yml with a multiline text that should not be translatable'
  mapping:
  copyrights:
      type: mapping
      label: 'Copyrights'
      # Copyrights should be kept in sync across all languages (=not translatable).
      translatable: false
      mapping:
        value:
          type: string
          label: 'Text'
          # Copyrights should be kept in sync across all languages (=not translatable).
          translatable: false
        format:
          type: string
          label: 'Text format'

but the type: string is not represented as multiline.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet