Exodus's depth charge's anti-sub targeting is not shown in UI

### Describe the issue

The Exodus's depth charges can only target submerged units (unlike the Tempest, torpedo bomber, or CZAR depth charges)
https://github.com/FAForever/fa/blob/0a8c75f623f1ef6ded9bfecb22b739431cb49e4f/units/UAS0201/UAS0201_unit.bp#L238

This is not shown in the UI, and it is confusingly labeled as "Anti Navy".

### Expected Behavior

1. A possible solution would be to rename the weapon category to "Anti Sub" and fix anything that relied on "Anti Navy" before.
- This may include unit dbs.
2. Another solution would be to abandon the weapon category field for UI usage and just parse the fire target layers table.
- A Sim/UI compatible utility helper function that does the parsing could be useful for AI usage and modded UIs.
- This would be advantageous for modded units, especially hybrid weapons that target multiple domains.
- A limitation for the UI would be that the sim can change the target layers of a weapon, although it is used sparsely in the base game for dummy weapons that control unit AI, it could be more impactful in mods. Allowing custom weapon categories bypasses this limit.
3. Changing the depth charges to target surface naval units would be a huge balance change, as they cannot be blocked by torpedo defenses and deal 88 DPS compared to the Exodus torpedo's 75 DPS.

### Screenshots

_No response_