Convert all E2E fileops tests to integration tests, leave single application with both agent types.

[t4lz]

• Remove the multi-value test argument from test_file_ops:
  

  mirrord/tests/src/file_ops.rs

  Line 20 in 8c089ac

  #[values(FileOps::Python, FileOps::Rust)] ops: FileOps,

• Use only the Rust app in E2E.

• For Rust and Python: Create separate apps for read, write, lseek, and faccessat, like the go apps:
  

  mirrord/mirrord/layer/tests/common/mod.rs

  Lines 581 to 592 in 8c089ac

  	Go18Read,
  	Go19Read,
  	Go20Read,
  	Go18Write,
  	Go19Write,
  	Go20Write,
  	Go18LSeek,
  	Go19LSeek,
  	Go20LSeek,
  	Go18FAccessAt,
  	Go19FAccessAt,
  	Go20FAccessAt,

  
  (RustRead, PythonRead, RustWrite, etc.)

• If we're lucky, those operations are similar in Rust, Python and Go and we can just add those apps to the existing tests for Go (and rename the tests), but more likely, we would have to create new tests for the new apps.