Feature: template in configuration file

[kparasch]

This is an unfinished example of a Template class the replicates a specific class in the configuration:

example config:

- class: pyaml.configuration.template.Template
  template: |
    class: pyaml.magnet.hcorrector.HCorrector
    name: %template_parameter%
    model:
      class: pyaml.magnet.linear_model.LinearMagnetModel
      unit: rad
      hardware_unit: str
      calibration_factor: 1.0
      powerconverter: MAGNET/%template_parameter%/B1L
  string_to_replace: "%template_parameter%"
  parameter_list:
    - PKDK_WL_108
    - PKDK_WL_93
    - PKDK_WL_79
    - PKDK_WL_64

During building, the factory would instead build now 4 objects.

This required a few simple changes, but there are a lot of edge cases that are not checked.

• I had the class be an iterator and treat it as a specific case in the Factory in order to avoid a configuration that would be built like: [[tobj1, tobj2, ...,] object 1] and instead have it be: [tobj1, tobj2, ..., object 1]
• Because the Template generates an object that is different to the Template class, new function had to be overloaded instead of init. This meant handling this case in the validation.

An example building script and configuration file can be found in pyaml/examples/template.