util: replacement to `context.WithCancel` that introduces a stack trace in the cancellation error

Discussed/proposed by @ecwall

Since we use go 1.20 we can re-implement a better `WithCancel` as follows:

```go
func WithCancel(ctx context.Context) (context.Context, func()) {
ctx, cancelFn := context.WithCancelCause(ctx)
simpleCancelFn := func() {
// Ensure that the stack trace at the time of cancellation is included in the error.
enhancedError := errors.WithStack(context.Canceled)
cancelFn(enhancedError)
}
return ctx, simpleCancelFn
}
```

Then we would have a linter that enforces we use this version everywhere instead of the stdlib.

Similarly we probably want to build a new custom version of `context.WithTimeout` which does something similar.

Jira issue: CRDB-31455

Epic CRDB-60947

Start by locating the existing uses of context.WithCancel and context.WithTimeout and reviewing how cancellation errors are handled. Done would include agreed custom replacements, adoption across the relevant uses, and a linter enforcing the intended APIs.

Written by the indexing model from the issue text.