[FIX] web: MonetaryField: input should be visible

Before this commit, the monetary input was invisible because its
width was 0.

After this commit, the input is visible.

Part-of: odoo/odoo#78221

addons/web/static/src/views/fields/monetary/monetary_field.xml

@@ -3,9 +3,9 @@
 
     <t t-name="web.MonetaryField" owl="1">
         <span t-if="props.readonly" t-esc="formattedValue" />
-        <div class="text-nowrap" t-else="">
+        <div class="text-nowrap d-inline-flex w-100" t-else="">
             <span t-if="!props.hideSymbol and currencyPosition === 'before'" t-out="currencySymbol" />
-            <input t-ref="numpadDecimal" t-att-id="props.id" t-att-type="props.inputType" t-att-placeholder="props.placeholder" class="o_input"/>
+            <input t-ref="numpadDecimal" t-att-id="props.id" t-att-type="props.inputType" t-att-placeholder="props.placeholder" class="o_input flex-grow-1 flex-shrink-1"/>
             <span t-if="!props.hideSymbol and currencyPosition === 'after'" t-out="currencySymbol" />
         </div>
     </t>