* Enable location sharing in Element

* Update roles/custom/matrix-client-element/tasks/validate_config.yml

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

* Update roles/custom/matrix-client-element/tasks/setup_install.yml

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

* Rename location sharing vars to be consistent with other vars

* Rename style.json to map_style.json

* Add m.tile_server section to /.well-known/matrix/client

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

This paves the way for installing other roles into `roles/galaxy` using `ansible-galaxy`,
similar to how it's done in:

- https://github.com/spantaleev/gitea-docker-ansible-deploy
- https://github.com/spantaleev/nextcloud-docker-ansible-deploy

In the near future, we'll be removing a lot of the shared role code from here
and using upstream roles for it. Some of the core `matrix-*` roles have
already been extracted out into other reusable roles:

- https://github.com/devture/com.devture.ansible.role.postgres
- https://github.com/devture/com.devture.ansible.role.systemd_docker_base
- https://github.com/devture/com.devture.ansible.role.timesync
- https://github.com/devture/com.devture.ansible.role.vars_preserver
- https://github.com/devture/com.devture.ansible.role.playbook_runtime_messages
- https://github.com/devture/com.devture.ansible.role.playbook_help

We just need to migrate to those.

showLabsSettings is the new enableLabs I guess. enableLabs doesn't seem to do anything anymore. It had been deprecated for a while.

This PR also removes @riot-bot:matrix.org as the default welcome_user_id since it doesn't exist anymore.

Fixes #586 (Github Issue)