Support first line number option in code block macro

As a Viewport manager, I want to decide what the first line number in the code block macro is, so I can better contextualize the code shown in my documentation.

Acceptance criteria:

• Support the ‘first line number’ configuration in the Confluence code block macro

Please refer to https://k15tintra.atlassian.net/browse/IVPRT-1790 for support of other code block macro configurations.