Passes values by reference when sorting to reduce memory copying. The
main saving on this is preventing copying of the large vector of files
getting passed into the `sort` function and then copying each item in
the vector in the for. This results in about a 27% performance gain
reducing the full benchmark of the kubernetes benchmark by 7.89 sec
Before
| Name | Total | Average | Min | Max |
| ---------------------------- | ------------- | ------------- | ------------- | ------------- |
| ivy_match(file.lua) 1000000x | 02.351614 (s) | 00.000002 (s) | 00.000002 (s) | 00.000042 (s) |
| ivy_files(kubernetes) 100x | 32.704256 (s) | 00.327043 (s) | 00.289397 (s) | 00.344413 (s) |
After
| Name | Total | Average | Min | Max |
| ---------------------------- | ------------- | ------------- | ------------- | ------------- |
| ivy_match(file.lua) 1000000x | 02.353386 (s) | 00.000002 (s) | 00.000002 (s) | 00.000049 (s) |
| ivy_files(kubernetes) 100x | 24.809576 (s) | 00.248096 (s) | 00.203167 (s) | 00.270263 (s) |
