[FIX] account: reconciliation_widget: rounding of reconciliation_amount computation

Use case:
- a tax of 10%, computation method: percentage of tax included
- a account_reconciliation_model with an amount of 90%
- make a statement of 1.31 (or something weird when it comes to digits)
- reconcile it with a counterpart
- prefill that counterpart with the account_reconciliation just created
- push on reconcile

Before this commit, the amount that was computed was not rounded, resulting in making unbalanced account_moves (by 0.001)
This was invisble since the display of monetary is rounded
After this commit, the rounding is done according to the currency's parameters and produces correct move_lines

OPW 751881

addons/account/static/src/js/account_reconciliation_widgets.js

@@ -763,7 +763,9 @@ var abstractReconciliationLine = Widget.extend({
             else if (preset_line.amount_type === "percentage") {
                 self.amount_field.set_value(0);
                 self.updateBalance();
-                self.amount_field.set_value(-1 * self.get("balance") * preset_line.amount / 100);
+                var currency_dict = session.get_currency(self.get("currency_id"));
+                var preset_amount = utils.round_currency(currency_dict, -1 * self.get("balance") * preset_line.amount / 100);
+                self.amount_field.set_value(preset_amount);
             }
         }
     },

addons/web/static/src/js/framework/utils.js

@@ -350,6 +350,15 @@ function round_decimals (value, decimals) {
     return round_precision(value, Math.pow(10,-decimals));
 }
 
+/* Rounds a value according to a currency's digits
+ * @param {dict} The dict containing the currency's info, usually retrieved with session.get_currency
+ * @param {Number} The value to be rounded
+ */
+function round_currency(currency_dict, value) {
+    var digits = currency_dict && currency_dict.digits[1] || 4;
+    return round_decimals(value, digits);
+}
+
 function float_is_zero (value, decimals) {
     var epsilon = Math.pow(10, -decimals);
     return Math.abs(round_precision(value, epsilon)) < epsilon;
@@ -516,6 +525,7 @@ return {
     human_number: human_number,
     round_precision: round_precision,
     round_decimals: round_decimals,
+    round_currency: round_currency,
     float_is_zero: float_is_zero,
     confine: confine,
     assert: assert,