Relation Custom Fields on StockLocation not Updating

[dylviz]

Describe the bug
Update() method in stock location service file is missing call to update the relations. See code here:

vendure/packages/core/src/service/services/stock-location.service.ts

Line 89 in 9c1cb16

async update(ctx: RequestContext, input: UpdateStockLocationInput): Promise<StockLocation> {

To Reproduce

1. Create a custom relation on the StockLocation entity within your plugin
2. Run dev-server, open admin-ui
3. Modify the customField on StockLocation entity then click Update()
4. Navigate away from the page and back again and see that your update is not shown
5. This is because your update wasn't saved
6. verified in the DB that the updated relation is not modified/saved

Expected behavior
Updated relation should be shown in the admin-ui and in the DB StockLocation table

Environment (please complete the following information):

• Verified bug on V2.1.7 and V2.2.0
• @vendure/core version: > 2.1.7+

Additional Context
Will link PR

[dylviz]

Sorry, it's not letting me edit the issue to link the PR: #2805