[ENG-919] Custom Indexer Breaks things

[0xnim]

Describe the bug

In the gui it just says job fails if i use a custom indexer rule.

Reproduction

1. Create a new indexer rule
2. Add a location with that indexer rule enabled
3. Job says failed

Expected behavior

It is supposed to index the directory while following the rule.

Platform and versions

8.6.6
cargo 1.70.0 (ec8a8a0ca 2023-04-25)
rustc 1.70.0 (90c541806 2023-05-31)

Arch Linux x86_64
6.4.1-arch2-1

Stack trace

2023-07-12T09:29:44.908348Z ERROR sd_core::job::worker: Job<id='8c619c47-d61c-49aa-a6de-dd7e008f2270', name='indexer'> failed with error: Indexer(
    IndexerRules(
        MissingField(
            MissingFieldError(
                "indexer_rule.default",
            ),
        ),
    ),
);

### Additional context

_No response_

<sub>[ENG-919](https://linear.app/spacedriveapp/issue/ENG-919/custom-indexer-breaks-things)</sub>