Deprecated/moved functions in collections::str

* Deprecated `str::from_utf8_owned` in favor of `String::from_utf8`
* Deprecated `str::from_utf8_lossy` in favor of `String::from_utf8_lossy`
* Deprecated `str::from_utf16` in favor of `String::from_utf16`
* Deprecated `str::from_utf16_lossy` in favor of `String::from_utf16_lossy`
* Deprecated `str::from_chars` in favor of `String::from_chars`
* Deprecated `str::from_char` in favor of `String::from_char` and `.to_string()`
* Deprecated `str::from_byte` in favor of `String::from_byte`

[breaking-change]