Add additional headers

[sergeyshaykhullin]

Add XQueueMode, XQueueType, XQuorumInitialGroupSize, XSingleActiveConsumer and XOverflow header constants

Proposed Changes

I used a lot my own headers class, but discovered that you have one. I added some missed headers

Links to check headers:

• https://www.rabbitmq.com/quorum-queues.html
• https://www.rabbitmq.com/lazy-queues.html
• http://next.rabbitmq.com/consumers.html#single-active-consumer
• https://www.rabbitmq.com/maxlength.html#default-behaviour

Types of Changes

• Bug fix (non-breaking change which fixes issue #NNNN)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause an observable behavior change in existing systems)
• Documentation improvements (corrections, new content, etc)
• Cosmetic change (whitespace, formatting, etc)

Checklist

• 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

Further Comments

• Should i add this constants to APIApproval.Approve.approved.txt file?
• I'm not sure I wrote the comments correctly

[michaelklishin]

Thank you!

[michaelklishin]

@lukebakken @kjnilsson I assume this can be backported to 5.x?