Implemented logic to fetch default evaluation config from service model.

[lu-ohai]

This PR is a continue of #626.

Added api to fetch default evaluation config

• For offline model, read evaluation_config.json from service model object storage path.
• For deployed model, use:
  -- Job shapes from list_job_shapes: 1). use the same info for GPU and non-flex CPU shape 2). use the default ocpus and memory in gbs for flex CPU shape.
  -- Default model params
  -- Default block storage size

Notebook

• Deployed model

{'shape': {'VM.Standard2.1': {'block_storage_size': 100,
   'ocpus': 1,
   'memory_in_gbs': 15},
  'VM.Standard2.2': {'block_storage_size': 100,
   'ocpus': 2,
   'memory_in_gbs': 30},
  'VM.Standard2.4': {'block_storage_size': 100,
   'ocpus': 4,
   'memory_in_gbs': 30},
  'VM.Standard2.8': {'block_storage_size': 100,
   'ocpus': 8,
   'memory_in_gbs': 120},
  'VM.Standard2.16': {'block_storage_size': 100,
   'ocpus': 16,
   'memory_in_gbs': 240},
  'VM.Standard2.24': {'block_storage_size': 100,
   'ocpus': 24,
   'memory_in_gbs': 320},
  'VM.Standard.E3.Flex': {'block_storage_size': 100,
   'ocpus': 2,
   'memory_in_gbs': 32},
  'VM.Standard.E4.Flex': {'block_storage_size': 100,
   'ocpus': 2,
   'memory_in_gbs': 32},
  'VM.Standard3.Flex': {'block_storage_size': 100,
   'ocpus': 2,
   'memory_in_gbs': 32},
  'VM.Optimized3.Flex': {'block_storage_size': 100,
   'ocpus': 2,
   'memory_in_gbs': 32},
  'VM.GPU2.1': {'block_storage_size': 100, 'ocpus': 12, 'memory_in_gbs': 72},
  'VM.GPU3.1': {'block_storage_size': 100, 'ocpus': 6, 'memory_in_gbs': 90},
  'VM.GPU3.2': {'block_storage_size': 100, 'ocpus': 12, 'memory_in_gbs': 180},
  'VM.GPU3.4': {'block_storage_size': 100, 'ocpus': 24, 'memory_in_gbs': 360},
  'BM.GPU2.2': {'block_storage_size': 100, 'ocpus': 28, 'memory_in_gbs': 192},
  'BM.GPU.T1.2': {'block_storage_size': 100,
   'ocpus': 32,
   'memory_in_gbs': 1024},
  'BM.GPU3.8': {'block_storage_size': 100, 'ocpus': 52, 'memory_in_gbs': 768},
  'BM.GPU4.8': {'block_storage_size': 100, 'ocpus': 64, 'memory_in_gbs': 2048},
  'BM.GPU.A10.4': {'block_storage_size': 100,
   'ocpus': 64,
   'memory_in_gbs': 1024},
  'VM.GPU.A10.1': {'block_storage_size': 100,
   'ocpus': 15,
   'memory_in_gbs': 240},
  'VM.GPU.A10.2': {'block_storage_size': 100,
   'ocpus': 30,
   'memory_in_gbs': 480},
  'VM.Standard.A1.Flex': {'block_storage_size': 100,
   'ocpus': 2,
   'memory_in_gbs': 32}},
 'model_params': {'max_tokens': 500,
  'temperature': 0.7,
  'top_p': 1.0,
  'top_k': 50},
 'default': {'ocpus': 2, 'memory_in_gbs': 32, 'block_storage_size': 100}}