Run has duplicate field - unique ID

## Background
For historical reasons the `Run`'s `uniqueId` field is duplicated in `controlMeasure.runUniqueId` as it represents the contents of the `_INFO` file. The `_INFO` file references the run's unique ID, so a `conformance` job can find the correct `standardization job` to continue from, as `standardization + conformance` together constitute a single run.

## Feature
We should reduce this noise and only keep one field.

## Proposed Solution [Optional]
Solution Ideas
1. We can remove the top level field `uniqueId` OR
1. We can not include the `controlMeasure.runUniqueId` from the `_INFO` file
1. ~~We might just use the `Spark application ID`~~
1. We should make this field non-optional
1. Maybe we can just have a separate file (e.g. `_MENAS_RUN`), written by `Standardization` and read by `Conformance` to link the two spark jobs that doesn't need to be propagated to publish.