Python: Add json schema handling. Add experimental tag to OpenAPI and Memory Connectors.

[moonbox3]

Motivation and Context

The Python code base could handle some primitive types for the schema for tool call objects and kernel parameter metadata. However, it couldn't properly handle the more complex JSON schemas for tool call objects.

Description

This PR introduces:

• JSON schema handling for KernelParameterMetadata and tool call objects.
• Updates to the tool call utils method to properly recurse on the KernelParameterMetadata's stucture.
• Adds unit tests for this code.
• Add experimental_class/experimental_functions to various parts of the code base like Memory Connectors and OpenAPI plugin.
• Fixes Python: Kernel function can only be called with primitive parameters. Class parameters don't work. #6310
• Fixes Python: missing more advanced json schema serializer #6280

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄

[eavanvalkenburg]

Good work! Some minor notes!

[markwallace-microsoft]

Python 3.10 Test Coverage Report •

File	Stmts	Miss	Cover	Missing
semantic_kernel
kernel.py	262	50	81%	122, 124, 190, 197–206, 236, 246–254, 326–362, 432–433, 660, 681–683, 719, 721, 731
kernel_pydantic.py	9	1	89%	6
semantic_kernel/connectors/ai/google_palm/services
gp_text_embedding.py	32	6	81%	34–35, 61–62, 71–72
semantic_kernel/connectors/ai/hugging_face/services
hf_text_embedding.py	21	21	0%	3–60
semantic_kernel/connectors/ai/open_ai/services
open_ai_text_embedding.py	22	3	86%	55–56, 85
open_ai_text_embedding_base.py	19	1	95%	45
utils.py	20	14	30%	20–30, 38–53
semantic_kernel/connectors/openapi_plugin
openapi_function_execution_parameters.py	26	1	96%	36
openapi_manager.py	345	140	59%	105–111, 114–131, 134–136, 139–152, 155–166, 169–181, 208, 224, 237, 271, 276, 280, 356, 379, 382, 411, 479, 482–483, 491–492, 518–520, 526–527, 533–547, 551–567, 570–572, 575–577, 585–628, 691–724
semantic_kernel/functions
kernel_function_from_method.py	85	6	93%	128, 147–148, 154, 157–158
semantic_kernel/memory
memory_query_result.py	24	9	62%	45–52, 68
memory_record.py	47	17	64%	46–54, 76, 108, 121, 125, 129, 133, 137, 141
memory_store_base.py	11	3	73%	13, 16, 20
null_memory.py	15	5	67%	19, 31, 35, 45, 49
semantic_text_memory.py	35	19	46%	30–32, 55–67, 92–104, 120–121, 144–153, 161
volatile_memory_store.py	98	63	36%	32–35, 45, 56–57, 68, 80–85, 97–103, 116–128, 143–153, 165–171, 183–188, 208, 236–279
semantic_kernel/schema
kernel_json_schema_builder.py	45	2	96%	32, 57
TOTAL	6260	1039	83%

Python 3.10 Unit Test Overview

Tests	Skipped	Failures	Errors	Time
1341	1 💤	0 ❌	0 🔥	12.712s ⏱️

[eavanvalkenburg]

Some nits, nothing major