[3] Testnet light client debug/shortcut dropdown menu

**Is your feature request related to a problem? Please describe.**
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]

When using the light client on a private testnet, the lack of URL navigation (which is present in the web ui) prevents working around application initialization errors & missing data pages (such as USD_BTS market default pair of which both won't exist in a testnet).

**Describe the solution you'd like**
Either the ability to display and modify the URL bar within the light client, or a semi-hidden debug drop-down menu to navigate directly to specific pages within the client?

**Describe alternatives you've considered**

Compile web wallet for private testnet UI access, perhaps the UI is expecting a different testnet configuration? Perhaps a more dynamic testnet detection/switch over process?

Possible to navigate through the developer console?

Using a different client build, perhaps it won't have the testnet application initialization issues?

**Additional context**
N/A

Start with the light client and compare its navigation behavior with the web UI, including the URL bar and developer console entry points mentioned in the issue. Done means a clearly scoped approach for reaching specific pages on a private testnet without the reported initialization or missing-data blockage.

Written by the indexing model from the issue text.