Add file size info in the status bar

[nidhiii128]

When a file is opened, show “File size: 2.3 MB”.

[hajdam]

Hi, status bar contains already size in bytes which should be sufficient for information about the size of the file.
At best I would consider adding this information into status bar document size tooltip and properties dialog so if you are suggesting this to be a task as a part of hacktoberfest, it would be acceptable.