More DAQ metadata fields and new Image Process metadata field.

[YooSunYoung]

Fixes #55

Implemented

• Normalized/ob/sample
  This is implemented as a result_type in ImageProcessMetadata.

• Processing steps [list of strings]
  This is implemented as a processing_steps in ImageProcessMetadata.

• PI name [dict: name, email and orcid]

• Local contact [dict: name, email and orcid]

• Team members [list of dicts: name, email and orcid]

• Experiment number
  This is implemented as a experiment identifier

Not Implemented

• List of run numbers, dict of key/values for ob/sample runs
  I added description field in the ExperimentIdentifier schema. Users can encode which run type it was in that description.
  But keeping track of parents/children relation between dataset should be done by the cataloguing system.
  Because it is not guaranteed that the user of the data has access to the parents/related files locally but it is always guaranteed that they have access to the related dataset if they are on the catalouging system.
  The file should carry the minimum indicator for quick checking and shouldn't be considered the source of truth.
• Proton charge
• Scintillator type
  This can be encoded as a detector type, no?
• Sample/motor position
  I'm not sure if this is useful metadata. If it's physically meaningful to the image, it can be included in the coordinate.
• Detector offset (timepix 1)
  Same as the sample/motor position