[fs] File Operations for MINIX File System

[ppenna]

Description

We should provide the following directory operations for a MINIX file system:

• [ ] file_create(): creates a regular file
• [x] file_open(): opens a regular file (ace3514e45bf40bd74698d14198e3db0b9cb213e)
• [ ] file_close(): closes a regular file (ace3514e45bf40bd74698d14198e3db0b9cb213e)
• [ ] file_unlink(): removes a regular file
• [x] file_read(): reads data from a regular file (ace3514e45bf40bd74698d14198e3db0b9cb213e)
• [x] file_write(): writes data to a regular file (ace3514e45bf40bd74698d14198e3db0b9cb213e)
• [x] file_skeek(): reposition read/write regular file offset (ace3514e45bf40bd74698d14198e3db0b9cb213e)