Refactor code for routing and navbar using a dictionary with pageName-viewName

Created by: kousiksatish

This is a technical issue related to code management.

Current snippets of code:

# In App.js
<Route exact path="/links" render={(props) => <Links {...props}/>} />
<Route exact path="/summary" render={(props) => <Summary {...props}/>} />
<Route exact path="/clusters" render={(props) => <Cluster {...props}/>} />

# In navbar.js
<Link
  to="/clusters"
  onClick={() => {
    setView("Clusters");
  }}
>
  <span {...navLinkProps('/clusters', 0.3)}>
    Clusters
  </span>
</Link>

<Link
  to="/links"
  onClick={() => {
    setView("Helpful Links");
  }}
>
  <span {...navLinkProps('/links', 0.4)}>
    Helpful Links
  </span>
</Link>

As discussed in earlier PR https://github.com/covid19india/covid19india-react/pull/291 , this can be written in following way which will be better:

• Create a dictionary with ViewName, Pathname key value pair to be used across the project, including in App.js and Navbar.js . Loop through this dictionary in both places.
• In Navbar js create a new component for these links and create them by looping through the above mentioned dictionary.

We can reduce redundancy of code this way and also make adding new Views/Links easier.