Fix file watcher infinite loops and improve logging for local invoke

[roger-zhangg]

Problem

The AWS SAM CLI file watcher was experiencing infinite loops during local development, particularly with LoopBack applications that create temporary .sandbox directories. This caused:

• Extremely slow local invoke startup times (8+ minutes in some cases)
• High CPU usage from continuous file system events
• Poor developer experience during local development

Solution

This PR implements two key improvements:

1. Configurable Ignore Patterns for File Watching

• Added centralized ignore patterns to prevent infinite loops from temporary files and directories
• Environment variable control via SAM_CLI_FILE_OBSERVER_IGNORE_PATTERNS (default: enabled)
• Smart filtering that ignores internal package changes but still detects new packages

Default ignore patterns:

*/node_modules/*/*    # Ignore changes within packages, but allow new packages
*.tmp                 # Ignore temporary files  
*.temp                # Ignore temporary files
*/.git/*              # Ignore git directories
*/__pycache__/*       # Ignore Python cache
*.pyc                 # Ignore Python compiled files
*.log                 # Ignore log files

2. Enhanced Lock Acquisition Logging

• More specific debug messages showing what resources are being processed
• Function and resource context in lock acquisition logs
• Better debugging experience for file watcher issues

Usage

Default behavior (recommended):

sam local start-api

Disable ignore patterns for debugging:

SAM_USE_IGNORE_PATTERN =false sam local start-api

Windows Installation Instructions

For Windows users experiencing file watcher performance issues:

1. Install from source (recommended for testing):

   git clone https://github.com/aws/aws-sam-cli.git
   cd aws-sam-cli

make init

./Make -Init

2. __Or install specific branch__ (if available):

```cmd
pip install git+https://github.com/aws/aws-sam-cli.git@hot-swap-fix

3. Verify the fix is working:

   # Should show improved logging and faster startup
   sam local start-api --debug

4. Environment variable usage in Windows:

   # PowerShell
   $env: SAM_USE_IGNORE_PATTERN ="true"
   sam local start-api
   
   # Command Prompt
   set SAM_USE_IGNORE_PATTERN =true
   sam local start-api

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[vicheey]

Should we provide a way for customer to provide customize ignore pattern? If none is provided, we can use the DEFAULT_IGNORE_PATTERNS.

[roger-zhangg]

Yes this should be the idea when we ship it. I will use this version to debug with customer first

[vicheey]

DO NOT MERGE.