* Fix openhpc_configless when set to false

Need to pass this through the bool filter so that string values are
interpreted as booleans.

* Remove conf-server command line option if configless mode is disabled

* nodegroups using nodesets - doesn't handle empty nodegroups

* cope with empty nodegroups/partitions

* make gres work again

* make node/partition parameters more greppable

* use features to simplify nodeset configuration

* add nodegroup.features

* add validation

* document nodegroup.features to README

* add better examples in README

* tidy up README

* fix validate task path

* fix lint error

* default partitions to nodegroups to make CI easier

* update molecule tests for openhpc_nodegroups

* remove checks from runtime now validation defined

* fix NodeName= lines missing newlines between them when multiple hostlists within a node group

* remove tests for extra_nodes

* allow missing inventory groups (as per docs) when validating nodegroups

* only run validation once

* remove test14 from CI - extra_nodes feature removed

* update complex test for new group/partition variables

* rename  openhpc_partitions.groups -> openhpc_partitions.nodegroups  for clarity

* output NodeName hostlists on single line to improve large BM scheduler perf

This reverts commit 0dec9d8.

* add support for upgrading database

* fix db upgrade check for initial deploy

* add mysql tool to support checking db status

* make slurm db service consistent

* make backup optional

* fix ansible-lint whinging

* fix upgrade code for mariadb in CI

* fix mariadb connections

* fix upgrade logic

* Fix readme typo

Co-authored-by: Matt Crees <matthew.crees1@gmail.com>

* fix upgrade logic

* explain upgrade logic

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Co-authored-by: Matt Crees <matthew.crees1@gmail.com>