Python/.NET: Add a common agent invoke api.

[westey-m]

Motivation and Context

Being able to different invoke agents using a common API is useful to build higher level code on top of.

Description

Adding a common Invoke method with a common Thread object.

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 😄

[markwallace-microsoft]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
semantic_kernel/agents
agent.py	150	22	85%	46, 53, 57, 66–77, 124, 129, 134, 139, 144, 148, 152, 156, 263–265, 332
semantic_kernel/agents/autogen
autogen_conversable_agent.py	117	15	87%	68, 74, 86, 88, 93–97, 271–272, 281–284
semantic_kernel/agents/azure_ai
agent_thread_actions.py	341	129	62%	142, 144, 179–182, 369, 371, 410–411, 437, 440–444, 447–459, 462–493, 499–506, 509–522, 538–569, 613, 616, 647–681, 744, 749–754, 774–781, 812–821, 864–876
azure_ai_agent.py	176	40	77%	92, 103–113, 118–123, 130–139, 150–156, 207, 209, 215, 226–231, 233, 235, 256–259, 329, 430, 528, 590
azure_ai_channel.py	41	3	93%	93, 120–121
semantic_kernel/agents/bedrock
bedrock_agent.py	244	51	79%	77–84, 93, 159, 296, 315, 331–334, 340, 342, 345, 350, 390, 422–442, 446, 486, 505–508, 510–513, 555, 566–567, 579, 615–626, 637, 654–667, 684–693
bedrock_agent_base.py	141	41	71%	101, 119–120, 145, 158–160, 187, 206–208, 213, 232–234, 239, 243–244, 264–266, 275, 294–298, 303, 322–326, 331, 343–345, 357–376
semantic_kernel/agents/channels
bedrock_agent_channel.py	79	2	97%	208–209
chat_history_channel.py	69	2	97%	147, 150
semantic_kernel/agents/chat_completion
chat_completion_agent.py	198	20	90%	70, 80, 86, 98, 100, 105–109, 167, 170, 180, 188–193, 202, 354, 420, 481
semantic_kernel/agents/open_ai
assistant_thread_actions.py	336	56	83%	107, 110, 113, 189, 191, 228–234, 405, 463, 480, 569–597, 611–620, 656–670, 682–683, 754, 759, 791
open_ai_assistant_agent.py	228	27	88%	93, 110–111, 119–124, 131–141, 152–158, 315, 328, 364, 527, 630, 729
TOTAL	21215	2454	88%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3335	5 💤	0 ❌	0 🔥	1m 37s ⏱️