Revisit right panel

[fedorov]

• add some light background color differentiating header of the collapsible section components
• add SeriesDescription under the slide preview in the left panel
• organize all settings into a dedicated settings panel

• replace gear icon with a bug icon

• reuse the gear icon to open a settings panel with all of the settings above

[fedorov]

Need to confirm that diagnosis is coming from code meaning and not from description!

[igoroctaviano]

Need to confirm that diagnosis is coming from code meaning and not from description!

Findings:

• Diagnosis/finding is always derived from CodeMeaning (from ConceptCodeSequence or annotation property code sequences).
• No place uses AnnotationGroupDescription, InterpretationDiagnosisDescription, or similar Description fields for diagnosis/finding.
• AnnotationGroupLabel is only used for display labels, not for diagnosis type.
  TEXT content items correctly use TextValue for free-text evaluations; Finding (121071) is a CODE item and its text comes from ConceptCodeSequence[0].CodeMeaning.

[fedorov]

Related to #190