Update `_mapdata` reference files to include the `map.jinja`
configuration sources.

The v5 `map.jinja` is a generic and configurable system to load
configuration values, exposed as the `mapdata` variable, from
different places:

- YAML files and templates from the fileserver for non-secret data
- pillars or SDB are preferred for secret data
- grains or `config.get`

The `map.jinja` optional sources are configured with compound targeting like
syntax `[<TYPE>[:<OPTION>[:<DELIMITER>]]@]<KEY>` with the following
default ordered sources:

- `Y:G@osarch`: YAML file and Jinja template named after `osarch` grain
- `Y:G@os_family`: YAML file and Jinja template named after `os_family` grain
- `Y:G@os` YAML file and Jinja template named after `os` grain
- `Y:G@osfinger` YAML file and Jinja template named after `osfinger` grain
- `C@{{ tplroot ~ ':lookup' }}`: dict retrieved with `salt["config.get"]`
- `C@{{ tplroot }}`: dict retrieved with `salt["config.get"]`
- `Y:G@id`: YAML file and Jinja template named after `osarch` grain

This is done by two new libraries:

- `libmatchers.jinja` provides the `parse_matchers` macro to parse
  strings looking like compound matchers, for example `Y:G@osarch`

- `libmapstack.jinja` provides the `mapstack` macro to load
  configuration from different sources described by matchers

Post-processing of `mapdata` variable can be done in a `parameters/post-map.jinja`.

The v5 `map.jinja` is documented in `docs/map.jinja.rst`.

BREAKING CHANGE: `map.jinja` now exports a generic `mapdata` variable

BREAKING CHANGE: The per grain parameter values are now under `TEMPLATE/parameters/`