Filter emtpy queryParams (#1881)

# Summary

Closes #1750 

**Proposal:**
- Filtering `queryParams` when they are empty

## To test
- Copy the link 'https://pr1881--gpswapui.review.gnosisdev.com/#/?referral='
- Empty URL queryParams will be removed.

src/custom/hooks/useFilterEmptyQueryParams.ts

@@ -0,0 +1,27 @@
+import { useEffect } from 'react'
+import { useHistory } from 'react-router-dom'
+import qs from 'qs'
+
+import useParsedQueryString from 'hooks/useParsedQueryString'
+
+/**
+ * When query parameter is empty will be filtered
+ *  example: ?referral=&paramFullfilled=123
+ *  result: {paramFullfilled: 123}
+ *
+ * @param queryParams The object to check
+ */
+function filterEmptyQueryValues(queryParams: { [s: string]: unknown }) {
+  return Object.fromEntries(Object.entries(queryParams).filter(([, v]) => v))
+}
+
+export function useFilterEmptyQueryParams() {
+  const queryParams = useParsedQueryString()
+  const history = useHistory()
+
+  useEffect(() => {
+    history.replace({
+      search: qs.stringify(filterEmptyQueryValues(queryParams)),
+    })
+  }, [history, queryParams])
+}

src/custom/pages/App/index.tsx

@@ -16,6 +16,7 @@ import * as Sentry from '@sentry/react'
 import { Integrations } from '@sentry/tracing'
 import { version } from '@src/../package.json'
 import { environmentName } from 'utils/environments'
+import { useFilterEmptyQueryParams } from 'hooks/useFilterEmptyQueryParams'
 
 const SENTRY_DSN = process.env.REACT_APP_SENTRY_DSN
 const SENTRY_TRACES_SAMPLE_RATE = process.env.REACT_APP_SENTRY_TRACES_SAMPLE_RATE
@@ -60,6 +61,9 @@ function createRedirectExternal(url: string) {
 }
 
 export default function App() {
+  // Dealing with empty URL queryParameters
+  useFilterEmptyQueryParams()
+
   return (
     <Wrapper>
       <Switch>