Reading or editing a file causes a large memory spike

[neubig]

When reading in a large file, we see a memory spike.

Probably this function would need to be made more general to read only the parts of the file that are necessary for the particular command:
https://github.com/All-Hands-AI/openhands-aci/blob/f9774a3ca86d2ec2430de5dbaef2cf657d48b826/openhands_aci/editor/editor.py#L381-L388

We should:

1. write tests that measure the memory usage when reading in or editing large files and see that they fail currently (e.g. read in a 10MB file and see that it requires over 10MB of memory)
2. modify the existing implementation to reduce memory requirements when editing only a small part of a larger file
3. run tests to make sure that they pass