Show datasource version in sources

[mdoering]

In the project/release sources view the title contains the version / issued date of the source used in the last sync (=dataset attempt). That is very useful information to look for sources that haven't been updated for a long time. It would be much better even if the issued date would be a distinct, sortable column!

I would also reorganize a few columns:

• issued as distinct column next to title
• name matches & estiamtes: move to the very end
• decision count: move next to sectors