Missing @record_function decorator and AutoGen instrumentation reliability issues in v0.4.14

# Missing @record_function decorator and AutoGen instrumentation reliability issues in v0.4.14

## Problem Description

We've identified two critical issues affecting users upgrading to AgentOps v0.4.14:

1. **Missing `@record_function` decorator**: The `@record_function` decorator that was available in previous versions is completely missing from v0.4.14, breaking existing user code that relies on manual instrumentation.

2. **AutoGen instrumentation reliability**: AutoGen support isn't working as expected due to incorrect version requirements and package naming confusion in the instrumentation configuration.

## Issue 1: Missing @record_function decorator

### Expected Behavior
Users should be able to use the `@record_function` decorator to manually instrument functions, as was available in previous versions.

### Current Behavior
The `@record_function` decorator is completely missing from the codebase. Attempting to import it results in:
```python
ImportError: cannot import name 'record_function' from 'agentops'
```

### Impact
- Breaks existing user code that relies on manual instrumentation
- No migration path or backward compatibility provided
- No documentation on what replaced this functionality

## Issue 2: AutoGen instrumentation reliability

### Expected Behavior
AutoGen instrumentation should work reliably with current AutoGen package versions and automatically track agent interactions.

### Current Behavior
- Minimum version requirement is set to "0.1.0" which is too low for real AutoGen packages
- Package naming confusion between "autogen", "ag2", and "autogen_agentchat" packages
- Import errors in examples indicate version compatibility issues
- Instrumentation may not activate due to incorrect version checks

### Evidence
1. **Incorrect version requirement**:
```python
# In agentops/instrumentation/__init__.py
"autogen": {"module_name": "agentops.instrumentation.ag2", "class_name": "AG2Instrumentor", "min_version": "0.1.0"}
```
The minimum version "0.1.0" is too low - AutoGen packages typically start from 0.3.x

2. **Import errors in examples**:
```python
# In examples/ag2/agentchat_with_memory.py
from autogen import ConversableAgent # This import fails
```

3. **Package ecosystem confusion**: The instrumentation targets "autogen" package but the ecosystem has evolved to include "ag2" and "autogen_agentchat" packages

## Root Cause Analysis

### @record_function Issue
- The decorator was removed during the v4.x migration without providing backward compatibility
- The functionality was replaced by the `@tool` decorator but no migration guide was provided
- No deprecation warning was added to help users transition

### AutoGen Issue
- The AutoGen ecosystem has evolved with multiple package variants (autogen, ag2, autogen_agentchat)
- Version requirements haven't been updated to reflect real package versions
- Examples use inconsistent import patterns indicating version compatibility problems

## Proposed Solution

### 1. Restore @record_function with backward compatibility
- Add `@record_function` decorator to the legacy module with deprecation warning
- Make it wrap the new `@tool` decorator for functionality
- Export it in the main `__init__.py` for backward compatibility

### 2. Fix AutoGen instrumentation
- Update minimum version requirements to realistic values (0.3.2 for autogen)
- Add support for multiple AutoGen package variants (autogen, ag2)
- Fix import issues in examples

## User Impact
- **High**: Existing code using `@record_function` is completely broken
- **Medium**: AutoGen users may experience unreliable instrumentation
- **Migration**: Users need clear guidance on transitioning from `@record_function` to `@tool`

## Testing Strategy
- Verify `@record_function` works with deprecation warning
- Test AutoGen instrumentation with corrected version requirements
- Run AutoGen examples to ensure they work correctly
- Verify session tracking generates proper AgentOps links

This issue affects users who rely on manual instrumentation and AutoGen integration, making it a blocking issue for upgrading to v0.4.14.