Drop IE11 support and remove unmaintained depends

Aside from letting us drop the legacy build it also
let's us drop the jquery-deparam dependency replacing
with built-in urlSearchParams

_includes/footer.html

@@ -1,5 +1,4 @@
 <!-- general behavior -->
-<script type="module" src="{{ site.baseurl }}/scripts/dist/modern/index.js"></script>
-<script nomodule src="{{ site.baseurl }}/scripts/dist/legacy/index.js"></script>
+<script type="module" src="{{ site.baseurl }}/scripts/dist/index.js"></script>
 
 <footer></footer>

package.json

@@ -10,11 +10,6 @@
       "engines": {
         "browsers": "defaults"
       }
-    },
-    "legacy": {
-      "engines": {
-        "browsers": "ie 11"
-      }
     }
   },
   "license": "MIT",
@@ -31,7 +26,6 @@
   "dependencies": {
     "bootstrap": "^5.0.2",
     "jquery": "^3.4.1",
-    "jquery-deparam": "^0.5.3",
     "lodash": "^4.17.11"
   }
 }

scripts/src/index.js

@@ -1,7 +1,6 @@
 /* global settings */
 import 'core-js/actual'
 import $ from 'jquery'
-import 'jquery-deparam'
 import 'bootstrap/js/dist/collapse'
 
 import DatasetsList from './components/datasets-list'
@@ -10,7 +9,11 @@ import OrganizationsFilter from './components/organizations-filter'
 import DatasetDisplay from './components/dataset-display'
 import {queryByComponent} from './util'
 
-const params = $.deparam(window.location.search.substr(1))
+const urlSearchParams = new URLSearchParams(window.location.search)
+const params = {}
+urlSearchParams.forEach((value, key) => {
+  params[key] = value
+})
 
 // Helper function to ensure datasets.json is only fetched once per page
 let datasetsCache