documentation: render nested return dicts for more then one level (#33143)

* Render nested return value documentation for more then one level
in the generated webdocs.

* Remove unnecessary code and cleanup

* Implement recursive option documentation

* Build elbow intendation style for options and return documentation

docs/docsite/_themes/srtd/static/css/theme.css

@@ -4748,7 +4748,7 @@ th, td {
 }
 
 table {
-       overflow-x: scroll;
+       overflow-x: auto;
        display: block;
        max-width: 100%;
 }
@@ -4864,3 +4864,48 @@ table {
         padding: 8px 13px;
     }
 }
+
+.outer-elbow-container {
+    display: flex;
+    height: 100%;
+    flex-direction: row;
+}
+
+.elbow-placeholder {
+    border-left: 1px solid #000;
+    height: 100%;
+    width: 30px;
+}
+
+.elbow-key {
+    height: 100%;
+    padding: 4px;
+    border-top: 1px solid #000;
+    flex-grow: 1;
+    border-left: 1px solid #000;
+}
+
+.elbow-blocker {
+    height: 0;
+    overflow: hidden;
+}
+
+.return-value-column {
+    height: 1px
+}
+
+.return-value-column td {
+    height: inherit
+}
+
+.cell-border {
+    padding: 4px;
+    border-left: 1px solid #000;
+    border-top: 1px solid #000;
+    height: 100%;
+}
+
+.documentation-table {
+    border-right: 1px solid #000;
+    border-bottom: 1px solid #000;
+}