Handle basic query parameters in connection URI

[captainju]

Proposed Changes

The current connection method setUri() does not handle query parameters at all, unlike the official Erlang client.
This pull request adds basic query parameters capabilities.
However, due to SSL handling differences between the Erlang client and the Java client, all SSL parameters are not used.
Only the following parameters are used:

• heartbeat : Heartbeat timeout value in seconds (an integer) to negotiate with the server.
• connection_timeout : Time in milliseconds (an integer) to wait while establishing a TCP connection to the server before giving up.
• channel_max : Maximum number of channels to permit on this connection.

(taken from https://www.rabbitmq.com/uri-query-parameters.html)

It is easily extendable for other future query parameters.

Types of Changes

What types of changes does your code introduce to this project?
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• Bugfix (non-breaking change which fixes issue #NNNN)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation (correction or otherwise)
• Cosmetics (whitespace, appearance)

Checklist

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the PR. If you're unsure about any of them, don't hesitate to ask on the
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• I have read the CONTRIBUTING.md document
• I have signed the CA (see https://cla.pivotal.io/sign/rabbitmq)
• All tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in related repositories

[michaelklishin]

Any reason to not use UTF-8 here?

[captainju]

I used the same charset as in uriDecode line 378, which is used to decode username password and vhost.

    private static String uriDecode(String s) {
        try {
            // URLDecode decodes '+' to a space, as for
            // form encoding.  So protect plus signs.
            return URLDecoder.decode(s.replace("+", "%2B"), "US-ASCII");
        }
        catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

https://github.com/rabbitmq/rabbitmq-java-client/pull/672/files#diff-045e321e0fb12f11085653a7ed09f16518f9f21a7c80990c30720958dc17e954R378

[michaelklishin]

@acogoluegnes FYI, I discussed this with @captainju on Slack and suggested that we would consider such a contribution.

[acogoluegnes]

Thanks!