Migrate to Mantine v8 and Design Changes (#961)

* mantine v8 migration

* various design changes and improvements

src/renderer/styles/ag-grid.css

@@ -0,0 +1,43 @@
+.ag-header-fixed {
+    position: fixed !important;
+    top: 65px;
+    z-index: 15;
+    padding: 0 2rem;
+    margin: 0 -2rem;
+    box-shadow: 0 -1px 0 0 #181818;
+    transition: position 0.2s ease-in-out;
+}
+
+.ag-header-window-bar {
+    top: 95px;
+}
+
+.ag-header {
+    z-index: 5;
+}
+
+.window-frame {
+    top: 95px;
+}
+
+.ag-header-transparent {
+    --ag-header-background-color: rgb(0 0 0 / 0%) !important;
+}
+
+.ag-header-fixed-margin {
+    margin-top: 36px !important;
+}
+
+.ag-header-cell-comp-wrapper {
+    margin: 0 0.5rem;
+}
+
+.ag-header-cell,
+.ag-header-group-cell {
+    padding-right: 0.5rem;
+    padding-left: 0.5rem;
+}
+
+.ag-header-cell-resize {
+    background-color: transparent;
+}