Enable stat operations for specific ranges

[r-scheele]

ref issue number: #1813

Stat() was designed to always work on the original file size, and not a portion of the object

[harshavardhana]

Please fix the tests @r-scheele

[klauspost]

2023-07-06T11:10:48.3248895Z === RUN   TestCoreCopyObject
2023-07-06T11:10:48.3294758Z ##[error]    core_test.go:472: Error: number of bytes in stat does not match, want 32768, got 0
2023-07-06T11:10:48.3304410Z --- FAIL: TestCoreCopyObject (0.03s)
2023-07-06T11:10:48.3304745Z === RUN   TestCoreCopyObjectPart
2023-07-06T11:10:48.3305160Z --- PASS: TestCoreCopyObjectPart (0.41s)
2023-07-06T11:10:48.3305442Z === RUN   TestCorePutObject
2023-07-06T11:10:48.3306219Z ##[error]    core_test.go:737: Error: number of bytes in stat does not match, want 32768, got 0
2023-07-06T11:10:48.3306961Z --- FAIL: TestCorePutObject (0.03s)

[r-scheele]

Hi @harshavardhana @klauspost please review again