Add collapsible view operations

[ryanhoangt]

W&B SWE agent uses an interesting approach to achieve top score on SWE-bench Verified, inspired by collapse a specific range in a code editor:

• open_module(path): view a file with all functions collapsed by default

Example output

• expand_function(path, fn_name): view that file again but with the fn_name function expanded

Example output

We can implement this by adjusting the str_replace_editor tool:

• Modify the view command on file path to print file content with functions collapsed by default
• Add an extra command expand_function