Review usage of `context.Background()` and pass down contexts

## Task summary

Newer code use contexts (`context.Context`) to cancel operations.
Unfortunately most of existing code does not and so we use `context.Background()` instead of passing down contexts from the caller,

We should review each usage of `context.Background()` and modify the calling code the pass down a context from its own caller.

EDIT: We should also check for `context.TODO()`

Search the repository for every use of context.Background() and context.TODO(), then trace each call to its caller and identify where a context can be passed down. Done means the usages have been reviewed and applicable calling code passes a caller-provided context instead of creating a background or placeholder context.

Written by the indexing model from the issue text.