Remove `legacySpacesDecode` from urlQueryToFilter

Remove `legacySpacesDecode` from urlQueryToFilter and remove it's
usages in analytics.

app/assets/javascripts/vue_shared/components/filtered_search_bar/filtered_search_utils.js

@@ -177,14 +177,10 @@ function filteredSearchTermValue(value) {
  * @param  {Object} options
  * @param  {String} [options.filteredSearchTermKey] if set, a FILTERED_SEARCH_TERM filter is created to this parameter. `'search'` is suggested
  * @param  {String[]} [options.filterNamesAllowList] if set, only this list of filters names is mapped
- * @param  {Boolean} [options.legacySpacesDecode] if set to true, plus symbols (+) are not encoded as spaces.
  * @return {Object} filter object with filter names and their values
  */
-export function urlQueryToFilter(
-  query = '',
-  { filteredSearchTermKey, filterNamesAllowList, legacySpacesDecode = false } = {},
-) {
-  const filters = queryToObject(query, { gatherArrays: true, legacySpacesDecode });
+export function urlQueryToFilter(query = '', { filteredSearchTermKey, filterNamesAllowList } = {}) {
+  const filters = queryToObject(query, { gatherArrays: true });
   return Object.keys(filters).reduce((memo, key) => {
     const value = filters[key];
     if (!value) {

ee/app/assets/javascripts/analytics/code_review_analytics/code_review_analytics_bundle.js

@@ -20,9 +20,7 @@ export default () => {
     labelsEndpoint: labelsPath,
     projectEndpoint: projectPath,
   });
-  const { milestone_title = null, label_name = [] } = urlQueryToFilter(window.location.search, {
-    legacySpacesDecode: true,
-  });
+  const { milestone_title = null, label_name = [] } = urlQueryToFilter(window.location.search);
   store.dispatch('filters/initialize', {
     selectedMilestone: milestone_title,
     selectedLabelList: label_name,

ee/app/assets/javascripts/analytics/cycle_analytics/index.js

@@ -28,9 +28,7 @@ export default () => {
     sort,
     direction,
     page,
-  } = urlQueryToFilter(window.location.search, {
-    legacySpacesDecode: true,
-  });
+  } = urlQueryToFilter(window.location.search);
 
   store.dispatch('initializeCycleAnalytics', {
     ...initialData,

ee/app/assets/javascripts/analytics/merge_request_analytics/index.js

@@ -35,9 +35,7 @@ export default () => {
     author_username = null,
     milestone_title = null,
     label_name = [],
-  } = urlQueryToFilter(window.location.search, {
-    legacySpacesDecode: true,
-  });
+  } = urlQueryToFilter(window.location.search);
   store.dispatch('filters/initialize', {
     selectedSourceBranch: source_branch_name,
     selectedTargetBranch: target_branch_name,

spec/frontend/vue_shared/components/filtered_search_bar/filtered_search_utils_spec.js

@@ -311,13 +311,6 @@ describe('urlQueryToFilter', () => {
       },
       { filteredSearchTermKey: 'search' },
     ],
-    [
-      'search=my+terms',
-      {
-        [FILTERED_SEARCH_TERM]: [{ value: 'my+terms' }],
-      },
-      { filteredSearchTermKey: 'search', legacySpacesDecode: true },
-    ],
     [
       'search=my terms&foo=bar&nop=xxx',
       {