New scans by tags

Closes daiquiri#27 (closed)

Closes #51 (closed)

This PR allows to define "new scan" buttons filtering scan actors by tags.

This allows the tomo tiling view to only launch scans tagged with tomo-tiling.

But this also can be used for other use cases.

The PR daiquiri!507 (merged) have to be merged before this one. Else the tomo demo and beamline will not working properly. But there will be no side effects on other applications.