Function: `FileOpen`

Opens a file for reading or writing and returns a file object for future operations

Method Signature

FileOpen(file=[string], mode=[string], charset=[string], seekable=[boolean])

Argument	Type	Required	Description	Default
`file`	`string`	`true`	The file to open.
`mode`	`string`	`false`	The mode to open the file in. Defaults to "read".	`read`
`charset`	`string`	`false`	The character set to use when reading or writing the file. Defaults to "utf-8".	`utf-8`
`seekable`	`boolean`	`false`	Whether the file should be opened as seekable. Defaults to false.