Strings should be filtered by Source too

[alinaKh]

When I use filter, it only searches in target column but not in the Source.
I didn't test if the filter works on Note.
I copy translation strings from the huge .xlsx file and desperately need full keyword search
Great tool otherwise. Thank you.

[remuslazar]

@alinaKh, thank you for the bug-report and.. yes, you're right, the filter should also search in the source column, I will fix that.

[alinaKh]

XliffFile.swift line 44:
for elementName in ["original", "target", "note"] {
replace with:
for elementName in ["source", "target", "note"] {