Add ability to prefix units to currency amounts

[quarkw]

This can be useful when copying amounts where the $ or other currency symbol comes before the numeric amount, as is standard in some countries

I did not change the default workflow configuration, so to actually use this, you would have to add a custom keyword to use the workflow, for example, conv.

And use it like:

conv $100 to EUR

Due to the way the converter works, the following would also work:
conv USD100 to EUR

For convenience, we could add all the currency symbols as keywords, but that may not be very maintainable when adding/removing new currencies. But, that would allow queries such as:
$100 to work automatically

[biati-digital]

Hi, thank's for the PR. This workflow was only created to avoid using keywords, having to add a keyword to use your changes defeats the entire purpose of the workflow.

I can not accept this PR but thank's anyway.

[quarkw]

Hi, thank's for the PR. This workflow was only created to avoid using keywords, having to add a keyword to use your changes defeats the entire purpose of the workflow.

I can not accept this PR but thank's anyway.

If I modified the PR to change the workflow configuration to work without keywords (work with the symbols automatically) would that be acceptable?