Nyzo 632: frozen edge in script response

Nyzo version 632 (commit on GitHub) adds the client's frozen edge to the script response.

This version affects the client.

When a user is interacting with a Nyzo script, knowing the frozen edge of the client can be helpful. In the graffiti example, this is demonstrated when pending transactions behind the client's frozen edge are eliminated. This causes new transactions to be generated to allow the user to resend pixels from transactions not successfully incorporated into the blockchain.

In NyzoScriptCommand, the frozen edge height from the BlockManager was added to the CommandTable for the result. This can be seen in the HTML version of the graffiti script result on the client.

In NyzoScriptState, the frozen edge height from the BlockManager was added to the JSON result produced by the renderJson() method. This can be seen in the API version of the graffiti script result on the client.

The frozenEdgeHeight field was added to the expected state strings in NyzoScriptStateTest.testSerialization().