Field and section type configuration changes

Configuration changes:

• Content Builder ships the Basic section type (basic), which can't be deleted. Untyped sections are Basic sections.
• Section types can let editors choose layouts: layout_locked, layout_options (with the type's own) and every_region, the blocks of every column.
• Field setting section_types is keyed by plugin ID, with the field's layouts for each type whose layout editors choose. The type's default layout is always offered. Lists are converted on save.
• Field settings disabled_layouts, allowed_layouts, block_categories and blocks are deprecated and unused. The update moves the first field's settings into Basic. Fields with other blocks, or without Basic's default layout, get their own section type. A site's own basic type becomes basic_2.
• New fields offer Basic.
• Section types store locked_layout_settings and layout_setting_options.
• Columns without a block limit store max_blocks: -1.
• Default values leave out reusable blocks. The Content block category is all or none.

Run drush updb and export configuration.
Modules whose layouts are in use can't be uninstalled. Replace the layout first on the Layouts in use page (permission administer layouts in use).