Spring-ai Add activation/deactivation auto-config property to all Model clients

Property is of format *.enabled= and is true by default. Note: the Bedrock clients are disabled by default.

• Add deactivation support for Vertex AI PaLM2 clients
• Add deactivation support for Azure OpenAI clients
• Add deactivation support for huggingface chat client
• Add deactivation support for Ollama clients
• Add deactivation support for OpenAI clients
• Add deactivation support for Stability Image and PostgresML clients
• Add deactivation support for ONNX Transformers Embedding client

It doesn't seems necessary to provide similar functionality to the VectorStore auto-configurations. Later are less likely to be mixed together and further more can use the existing exclude property.

Resolves #363

Comment From: tzolov

merged at 4e270ac75af055aa1e2f2de3f6a9fd80835b8af1