If you change the category code of the double quote character then you can define a macro that typesets "test"
as ``test''. In doing this, the only downside that I can see is that you will run into problems if you forget a closing quote. It is also not unlikely that this will cause havoc with some packages -- for example, double quotes are used by tikz so this will almost certainly not work if you want to use this in documents that also uses these features of tikz
. You'd really be better off using the recommended quoting style of LaTeX, which is to use repeated left and right quotation marks instead of double quotes. A global search and replace in any decent editor that supports regular expressions should fix your current document.
For completeness I have added a \quot
command to access the "real" double quote character and I have checked that accents like \"a
still work as expected.
Here's the code:
\documentclass{article}
\newcommand\quot{"}% allow access to the real double quote
\catcode`\"=13 % change the category code of "
\def"#1"{``#1''} % and make "stuff" expand to ``stuff''
\begin{document}
"test"
Universit\"at
You can also write \quot test\quot
\end{document}
and here is the output:

csquotes
and use\enquote{I am a wombat}
in your text.20%
the"
should not be used, use``
and''