[FIX] web, *: review kanban record sizes

* account, maintenance, mrp, payment, point_of_sale, sales_team

Previous system was:
- `flex: 1 1 300px;` on kanban records
- If a specific record needs a different size, add custom style to
  either change the `flex` rule or set a `min-width` for >=SM screens

Now:
- `flex: 1 1 auto;` and `width: 300px;` on kanban records
- If a specific record needs a different size, add custom style to
  change the `width` rule.

This allows some standardization of the way to customize the suited
width and also allow lesser LESS code (as the previous version required
either the use of the flex mixin or the use of a media query).

Note:
- Also remove useless app record rule
- Also fix MRP Work Centers record width

Note2:
This system should be improved for version 12.0.

addons/account/static/src/less/account_journal_dashboard.less

@@ -1,8 +1,6 @@
 .o_kanban_view.o_kanban_dashboard.o_account_kanban {
     .o_kanban_record {
-        @media (min-width: @screen-sm-min) {
-            min-width: 450px;
-        }
+        width: 450px;
 
         .oe_kanban_action_button {
             margin-bottom: 5px;

addons/maintenance/static/src/less/maintenance_team_dashboard.less

@@ -1,7 +1,5 @@
 .o_kanban_view.o_kanban_dashboard.o_maintenance_team_kanban {
     .o_kanban_record {
-        @media (min-width: @screen-sm-min) {
-            min-width: 420px;
-        }
+        width: 420px;
     }
 }

addons/mrp/views/mrp_workcenter_views.xml

@@ -143,7 +143,7 @@
                     <field name="oee_target"/>
                     <templates>
                         <t t-name="kanban-box">
-                            <div style="max-width: 250px; margin: 0 10px 10px" t-attf-class="#{kanban_color(record.color.raw_value)}">
+                            <div style="width: 400px;" t-attf-class="#{kanban_color(record.color.raw_value)}">
                                 <div t-attf-class="o_kanban_card_header o_kanban_record_top">
                                     <div class="o_kanban_record_headings o_kanban_card_header_title">
                                         <span name="wc_stages" class="pull-left">

addons/payment/static/src/less/payment_acquirer.less

@@ -1,9 +1,8 @@
 .o_kanban_view.o_kanban_payment_acquirer {
     &.o_kanban_ungrouped {
         .o_kanban_record {
-            @media (min-width: @screen-sm-min) {
-                min-width: 500px;
-            }
+            width: 500px;
+
             .o_kanban_image {
                 float: right;
 
@@ -59,4 +58,4 @@
     .o_warning_text {
         color: #f0ad4e;
     }
-}
+}

addons/point_of_sale/static/src/less/pos_dashboard.less

@@ -1,7 +1,5 @@
 .o_kanban_view.o_kanban_dashboard.o_pos_kanban.o_kanban_ungrouped {
 	.o_kanban_record {
-        @media (min-width: @screen-sm-min) {
-            min-width: 500px;
-        }
+        width: 500px;
 	}
 }

addons/sales_team/static/src/less/sales_team_dashboard.less

@@ -4,7 +4,7 @@
     @sale-table-spacing: 10px;
 
     .o_kanban_record {
-        .o-flex(1, 1, 450px);
+        width: 450px;
 
         .o_sales_team_kanban_graph_section {
             .o_graph_linechart {

addons/web/static/src/less/kanban_view.less

@@ -263,11 +263,6 @@
     // Provide a basic style for different kanban record layouts
     // ---------------------------------------------------------
     .oe_kanban_card, .o_kanban_record {
-        // Apps List records sizing
-        &.oe_module_vignette {
-            .o-flex(1, 1, 350px);
-        }
-
         // -------  v11 Layout + generic layouts (~v10) -------
         // Kanban Record - Dropdown
         .o_dropdown_kanban {
@@ -603,7 +598,8 @@
         padding: @o-kanban-record-margin (@odoo-horizontal-padding - @o-kanban-record-margin);
 
         .o_kanban_record {
-            .o-flex(1, 1, @o-kanban-default-record-width);
+            .o-flex(1, 1, auto);
+            width: @o-kanban-default-record-width;
             margin: (@o-kanban-record-margin * 0.5) @o-kanban-record-margin;
 
             @media (max-width: @screen-xs-max) {