Stylelint rules - allow flex and grid properties to be longhanded

[MAILPOET-2067]

.stylelintrc

@@ -21,10 +21,12 @@
     "comment-whitespace-inside": "always",
     "declaration-bang-space-after": "never",
     "declaration-bang-space-before": "always",
-    "declaration-block-no-duplicate-properties": [ true, {
+    "declaration-block-no-duplicate-properties": [true, {
       ignore: ["consecutive-duplicates-with-different-values"],
-    } ],
-    "declaration-block-no-redundant-longhand-properties": true,
+    }],
+    "declaration-block-no-redundant-longhand-properties": [true, {
+        ignoreShorthands: [/flex/, /grid/]
+    }],
     "declaration-block-semicolon-newline-after": "always-multi-line",
     "declaration-block-semicolon-space-after": "always-single-line",
     "declaration-block-semicolon-space-before": "never",

assets/css/src/components/_importExport.scss

@@ -135,7 +135,8 @@ tr {
 
   .mailpoet_import_selection_form {
     display: flex;
-    flex-flow: row nowrap;
+    flex-direction: row;
+    flex-wrap: nowrap;
 
     > * {
       margin-right: 2.5em;
@@ -164,7 +165,8 @@ tr {
 
   .mailpoet_import_method_paste {
     display: flex;
-    flex-flow: row nowrap;
+    flex-direction: row;
+    flex-wrap: nowrap;
   }
 
   .mailpoet_import_mailchimp {

assets/css/src/components/_settings.scss

@@ -17,8 +17,10 @@
       background-color: #fff;
       border: 2px solid #dcdcdc;
       display: flex;
-      flex: 1 1 0;
+      flex-basis: 0;
       flex-direction: column;
+      flex-grow: 1;
+      flex-shrink: 1;
       margin: 0 25px 25px 0;
       max-width: 500px;