Fix search pos on file with leading whitespace

[tom93]

This fixes a bug when using the File Editor's search feature on a file that contains leading whitespace. The bug is that when pressing the "<" and ">" buttons to go to the prev/next match, the cursor position is wrong -- it is shifted left by the amount of whitespace at the start of the file. (Note that this this about the cursor position; the highlighting does not have this issue.)

From the commit message:

The extension property EditText.value trims leading/trailing whitespace, so using it to calculate the locations of the search matches produces incorrect indices if the file has leading whitespace.

(This affects the cursor position when going to the next/prev match. It does not affect the highlighting of matches.)

[Aga-C]

Looks like it's working fine, but next time please add some demonstration video or screenshots (like it's asked in the template you've removed) if you aren't fixing any already raised bug. It saves us time on understanding the problem and comparing between versions, especially that here it wasn't so obvious.

[naveensingh]

Okay, looks good. Thanks :)