make Ollama be the default LLM provider for examples

[donbourne]

Making the examples default to using Ollama is probably easier for people to use than to require people to get an Azure cloud account.

We might want to keep the dependencies and properties (commented out) in case people want to switch to Azure, and include dependencies / properties for Ollama.

Add ollama dependency to examples:

        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-ollama</artifactId>
        </dependency>

Remove (or comment out) azure open ai dependency:

        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-azure-open-ai</artifactId>
        </dependency>

Add properties for the llm configuration in the microprofile-config.properties file with:

dev.langchain4j.plugin.chat-model.class=dev.langchain4j.model.ollama.OllamaChatModel
dev.langchain4j.plugin.chat-model.config.base-url=http://localhost:11434
dev.langchain4j.plugin.chat-model.model-id=llama3.2

Remove (or comment out) azure open ai properties