Bug 27719: Apply _escape_str and _escape_price where needed

Bug 27719: Apply _escape_str and _escape_price where needed

This bug replaces calls for .escapeHtml and format_price for there null
checking counterparts

To test:

1: have a fresh Koha Testing Docker
2: have a basket set to create item records on ordering
3: populate basket from a marc file, only setting price and fund for the items
4: close basket
5: click to Receive, create invoice
6: on parcel.pl, "Processing" alert never resolves
CHECK => The console shows:
parcel.pl?invoiceid=1:810 Uncaught TypeError: Cannot read property 'format_price' of null
    at render (parcel.pl?invoiceid=1:810)
    at datatables.min_20.1200012.js:57
    at Object.b.fnGetData (datatables.min_20.1200012.js:51)
    at B (datatables.min_20.1200012.js:56)
    at Ha (datatables.min_20.1200012.js:64)
    at P (datatables.min_20.1200012.js:68)
    at vb (datatables.min_20.1200012.js:79)
    at datatables.min_20.1200012.js:76
    at i (datatables.min_20.1200012.js:74)
    at Object.success (datatables.min_20.1200012.js:75)

And that error points toward:
                        "data": "replacement_price",
                        "render": function(data, type, row, meta) {
                            return (row.replacement_price).format_price();
                        },
                    },
7: apply patch
8: redo steps 5 and 6
SUCCESS => "Processing" alert doesn't hangs, and prices with null values
are empty.

Sponsored-by: Virginia Polytechnic Institute and State University
Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>