* Fix precondition of change set 97

Without the `type` and with the space Liquibase is unable to parse this
precondition.

During `lein test` it outputs:
```
[clojure-agent-send-off-pool-0] DEBUG liquibase.changelog - Running Changeset:migrations/000_migrations.yaml::97::senior
[clojure-agent-send-off-pool-0] DEBUG liquibase.executor - Changeset migrations/000_migrations.yaml::97::senior
[clojure-agent-send-off-pool-0] DEBUG liquibase.executor - Added 0.32.0
[clojure-agent-send-off-pool-0] INFO  liquibase.changelog - Marking ChangeSet: migrations/000_migrations.yaml::97::senior ran despite precondition failure due to onFail='MARK_RAN':
          liquibase.yaml : DBMS Precondition failed: expected null, got h2

[clojure-agent-send-off-pool-0] DEBUG liquibase.changelog - Skipping ChangeSet: migrations/000_migrations.yaml::97::senior
[clojure-agent-send-off-pool-0] DEBUG liquibase.executor - Executing with the 'jdbc' executor
[clojure-agent-send-off-pool-0] DEBUG liquibase.executor - 1 row(s) affected
```

After this change the output changes to:
```
[clojure-agent-send-off-pool-0] DEBUG liquibase.changelog - Running Changeset:migrations/000_migrations.yaml::97::senior
[clojure-agent-send-off-pool-0] DEBUG liquibase.executor - Changeset migrations/000_migrations.yaml::97::senior
[clojure-agent-send-off-pool-0] DEBUG liquibase.executor - Added 0.32.0
[clojure-agent-send-off-pool-0] INFO  liquibase.changelog - Marking ChangeSet: migrations/000_migrations.yaml::97::senior ran despite precondition failure due to onFail='MARK_RAN':
          liquibase.yaml : DBMS Precondition failed: expected mysql,mariadb, got h2

[clojure-agent-send-off-pool-0] DEBUG liquibase.changelog - Skipping ChangeSet: migrations/000_migrations.yaml::97::senior
[clojure-agent-send-off-pool-0] DEBUG liquibase.executor - Executing with the 'jdbc' executor
[clojure-agent-send-off-pool-0] DEBUG liquibase.executor - 1 row(s) affected
```

For documentation of the syntax cf.
 https://docs.liquibase.com/concepts/advanced/preconditions.html



* Extend migration linter to check dbms preconditions

* Also validate the `type` field of the `dbms` precondition

Co-authored-by: dpsutton <dan@dpsutton.com>