Falocalrepo

Changes

* Database version is checked for all `database` commands, but no exception is raised for `info` and `upgrade`

Changes

* Migrate to Python 3.9

Dependencies

* falocalrepo-database dependency set to [\~4.11.0](https://pypi.org/project/falocalrepo-database/4.11.0)
* falocalrepo-server dependency set to [\~1.9.0](https://pypi.org/project/falocalrepo-server/1.9.0)
* Solve issue 9

Changes

* Let `UnknownFolder` exceptions rise, exit with code 3 when caught
* Error codes that were 3 or greater have been moved up by 1
* 1 `MalformedCommand`, `UnknownCommand`
* 2 `MultipleInstances`
* 3 `UnknownFolder`
* 4 `ConnectionError`
* 5 `DatabaseError`, `IntegrityError`
* 6 `TypeError`, `AssertionError`
* 7 `Exception`, `BaseException`
* Exception `repr` is not printed if `FALOCALREPO_DEBUG` option is on

Fixes

* Fix `columns` option being ignore in database search commands
* Fix `columns` not being selected properly when used in conjunction with `json` option in database search commands

Changes

* Print environmental variables flags to stderr

Fixes

* Fix `KeyError`'s in search

Changes

* Add `json` and `columns` options to database search commands to output results in JSON format

Fixes

* Fix zero-padded ID's not being matched by search commands
* Fix possible output error during single submissions download