Bug 20395: Change paycollect to use Price formatter

Bug 20395: Change paycollect to use Price formatter

Test plan:
1) Apply patch
2) Go to Home -> Patrons -> Patron details (for any patron)
3) Create manual invoice for the patron
4) Pay fines -> Pay -button
5) Check that the currency values look correct

6) Pay fines -> Pay amount -button
7) Check that the currency values look correct

8) Pay fines -> Pay selected -button
9) Check that the currency values look correct

10) Change the CurrencyFormat setting
11) Repeat 2-9

Signed-off-by: Pasi Kallinen <pasi.kallinen@joensuu.fi>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>