Implement default metadata for components and adapters

This implements default metadata as specified in landtrans/landtech/management#233

@muellese Should we somehow try to get the actual slot metadata (like units, grid, ...) into here too? Not sure how to represent grids, but it could IMO be useful.
Done.

TODO:

• Update docs
• Add book section
• Overwrite/implement for existing components and adapters
• Update CHANGELOG
• Merge !273 (merged)

Example

{'adapters': {'Scale@2391719058640': {'class': 'finam.adapters.base.Scale',
                                      'in_info': {'grid': 'NoGrid (0D)',
                                                  'units': ''},
                                      'name': 'Scale',
                                      'out_info': {'grid': 'NoGrid (0D)',
                                                   'units': ''}},
              'Scale@2391719059168': {'class': 'finam.adapters.base.Scale',
                                      'in_info': {'grid': 'NoGrid (0D)',
                                                  'units': ''},
                                      'name': 'Scale',
                                      'out_info': {'grid': 'NoGrid (0D)',
                                                   'units': ''}}},
 'components': {'MockupComponent@2391719110688': {'class': 'test_schedule.MockupComponent',
                                                  'inputs': {},
                                                  'name': 'MockupComponent',
                                                  'outputs': {'Output': {'class': 'finam.sdk.output.Output',
                                                                         'has_targets': True,
                                                                         'info': {'grid': 'NoGrid (0D)',
                                                                                  'units': ''},
                                                                         'is_static': False,
                                                                         'name': 'Output'}}},
                'MockupDependentComponent@2391719111408': {'class': 'test_schedule.MockupDependentComponent',
                                                           'inputs': {'Input': {'class': 'finam.sdk.input.Input',
                                                                                'info': {'grid': 'NoGrid (0D)',
                                                                                         'units': ''},
                                                                                'is_static': False,
                                                                                'name': 'Input'}},
                                                           'name': 'MockupDependentComponent',
                                                           'outputs': {}},
                'MockupDependentComponent@2391719111696': {'class': 'test_schedule.MockupDependentComponent',
                                                           'inputs': {'Input': {'class': 'finam.sdk.input.Input',
                                                                                'info': {'grid': 'NoGrid (0D)',
                                                                                         'units': ''},
                                                                                'is_static': False,
                                                                                'name': 'Input'}},
                                                           'name': 'MockupDependentComponent',
                                                           'outputs': {}}},
 'links': [{'from': {'component': 'MockupComponent@2391719110688',
                     'output': 'Output'},
            'to': {'adapter': 'Scale@2391719059168'}},
           {'from': {'component': 'MockupComponent@2391719110688',
                     'output': 'Output'},
            'to': {'component': 'MockupDependentComponent@2391719111696',
                   'input': 'Input'}},
           {'from': {'adapter': 'Scale@2391719058640'},
            'to': {'component': 'MockupDependentComponent@2391719111408',
                   'input': 'Input'}},
           {'from': {'adapter': 'Scale@2391719059168'},
            'to': {'adapter': 'Scale@2391719058640'}}],
 'time_frame': [datetime.datetime(2000, 1, 1, 0, 0), None]}