Add minimum width for Fleet UI and "Pack" tables on "Host details" page and "Queries" table (#1701)

- Add `$min-app-width: 1200px` to define the minimum width of the Fleet UI. 
- Remove sort form the "Query name" column in the "Pack" tables on the **Host details** page
- Set static widths all column in the "Pack" tables on the **Host details** page except the "Query name" column to support the new minimum width
- Set static widths for all columns in the "Queries" table except the "Name" and "Author" columns to support the new minimum width

frontend/styles/global/_global.scss

@@ -60,7 +60,7 @@ a {
   @at-root {
     .has-sidebar & {
       margin-right: 0;
-      min-width: 760px;
+      min-width: calc(#{$app-min-width} - 30px - 30px - #{$sidepanel-width});
       max-width: calc(
         100vw - #{$pad-xlarge} - #{$pad-xlarge} - #{$pad-xxsmall} - #{$sidepanel-width}
       );

frontend/styles/var/_global.scss

@@ -1,4 +1,4 @@
 $border-radius: 4px;
 $base-font-size: 16;
 $sidepanel-width: 340px;
-$sidepanel-tablet-width: 340px;
+$app-min-width: 1200px;