Milestones: Version of the package vs version of the release train

[muratg]

Currently we name milestones based on the package version. However, with patch releases, we also have a "release" version.

For example, Diagnostics will release it's 1.0.1 patch in 1.0.3 patch train in LTS.

We can capture the train information as metadata in "Description" field of the milestone for these oddball cases. i.e. train: 1.0.3. And hubbup can use this to categorize milestones based on trains. (i.e. show Diagnostics in 1.0.3 column).