Add nav parameter to autocomplete

[marcosholgado]

Task/Issue URL: https://app.asana.com/0/1125189844152671/1200343978632902
Tech Design URL:
CC:

Description:
This PR introduces the new autocomplete parameter is_nav. The extra isNav=true field will then be used as a navigation query (meaning when the user clicks that autocomplete suggestion we load that URL). Results where this is false should be treated as searches (even if they look like a URL).

This PR also handles the case where nav=null in which case we default to the old way.

Steps to test this PR:
Previous steps, setting up Charles

1. Connect your device to charles and use the autocomplete.json response provided in the task.
2. Install and launch the app.
3. Add a bookmark to http://m.youtube.com
4. Do a search (i.e. you) and in Charles map the response to the autocomplete.json file.

Test cases

1. The bookmark result should take you to the URL.
2. The first autocomplete result has isNav=false, clicking on it should do a search.
3. The second autocomplete result has isNav=false and is a URL, clicking on it should do a search.
4. The third autocomplete result has isNav=true, clicking on it should load the URL.
5. The fourth autocomplete result doesn't have the nav attribute and is a URL, clicking on it should load the URL.
6. The fifth autocomplete result doesn't have the nav attribute and is a search term, clicking on it should do a search.

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Internal references:

Software Engineering Expectations
Technical Design Template

[CDRussell]

Tested and working well!