codeintel: add dashboard for precide-code-intel-worker total in-progress upload size

[Strum355]

Introduces a new panel in the precise-code-intel-worker dashboard for tracking the total in-progress uploads per-instance. This may help us in tracking correlation between in-progress uploads' size and resource usage for better instance sizing.

Follows on from @rafax: I think the guidance was "precise-code-intel-worker needs more than 3x the size of largest LSIF upload", but we don't have a metric that shows the size of attempted uploads - adding a metric for this would be useful.

Test plan

Tested locally, see picture:

TODO: see if theres any unit tests we can add

[sourcegraph-bot]

Codenotify: Notifying subscribers in CODENOTIFY files for diff 9d12958...54d3ef4.

Notify	File(s)
@beyang	enterprise/cmd/precise-code-intel-worker/internal/worker/handler.go enterprise/cmd/precise-code-intel-worker/internal/worker/worker.go
@bobheadxi	monitoring/definitions/shared/codeintel.go monitoring/definitions/shared/workerutil.go
@efritz	enterprise/cmd/frontend/internal/codeintel/httpapi/upload_handler.go enterprise/cmd/frontend/internal/codeintel/httpapi/upload_handler_multipart.go enterprise/cmd/frontend/internal/codeintel/httpapi/upload_handler_single.go enterprise/cmd/frontend/internal/codeintel/httpapi/upload_handler_state.go enterprise/cmd/frontend/internal/codeintel/httpapi/upload_handler_test.go enterprise/cmd/precise-code-intel-worker/internal/worker/handler.go enterprise/cmd/precise-code-intel-worker/internal/worker/worker.go internal/codeintel/stores/dbstore/uploads.go internal/codeintel/uploads/internal/store/scan.go internal/codeintel/uploads/internal/store/store_uploads.go internal/codeintel/uploads/shared/types.go lib/codeintel/upload/request.go lib/codeintel/upload/upload.go
@slimsag	monitoring/definitions/shared/codeintel.go monitoring/definitions/shared/workerutil.go
@sourcegraph/delivery	doc/admin/observability/dashboards.md monitoring/definitions/shared/codeintel.go monitoring/definitions/shared/workerutil.go

[efritz]

Should we use the uncompressed size for the budget instead in the future?

[Strum355]

ultimately yea I think so