Add title to property based on Joi meta property

[mattixittam]

The thing that led to this PR is the OpenAPI v3 AnyOf generation. In Redocly (which we use) at least this shows the type ('object', 'string', 'number') on the alternatives-selector by default.

To show a more descriptive label you can add the title property to each of the alternatives, which gets you something like this:

This PR adds support for the title-property to hapi-swagger through the title Joi.meta() property.

joiModel.meta({ title: 'SIF' })

I've added it very generically, as this property can be added to any schema in both OpenAPI 2 & 3, and display after the property type in Redocly:

status: Joi.string().meta({ title: 'QuotationStatus' }),

It was deceptively simple to add, so please let me know if I missed any edge-cases, added it to the wrong tests or did something else stupid :)

I did not check how this affects SwaggerUI display, but it seems that such an integral part of the OpenAPI def should just work :)

The meta property name title may be too generic, we could change it to swaggerTitle I guess.