feat: Update model_input_constants to add SambaNovaComponent

[edwinjosechittilappilly]

Add sambanova to models in agents.

This pull request includes changes to integrate SambaNova as a new model component in the backend. The most important changes include importing the SambaNova component, defining a function to get SambaNova inputs and fields, and updating the model providers dictionary to include SambaNova.

Integration of SambaNova component:

• src/backend/base/langflow/base/models/model_input_constants.py: Imported SambaNovaComponent from langflow.components.models.sambanova.
• src/backend/base/langflow/base/models/model_input_constants.py: Added a new function _get_sambanova_inputs_and_fields() to handle SambaNova inputs and fields.
• src/backend/base/langflow/base/models/model_input_constants.py: Updated the model providers dictionary to include SambaNova inputs and fields, and handle potential import errors.