Support additional R2DBC pool properties

[rodolphocouto]

This PR adds some missing properties from R2DBC pool:

• max-life-time
• max-acquire-time
• max-create-connection-time
• validation-depth

[snicoll]

Everyone, thank you for all the reviews, I think we're good now.

[snicoll]

Thanks for the PR. I've made some suggestions.

I didn't find the tests that exercice the mapping of those properties. Please see R2dbcAutoConfigurationTests.

[snicoll]

@rodolphocouto how is it going? Have you had a chance to look at the review?

[rodolphocouto]

Hey @snicoll, thanks for your review. I started working on that today and I should finish it soon.

[snicoll]

@rodolphocouto thanks for the follow-up. Are you done with d3d38d2? I am asking as I've requested to complete the existing tests to exercise the code you've added. Thanks!

[rodolphocouto]

I just added some tests on R2dbcProperties. I couldn't find a way to test ConnectionFactory or ConnectionPool because they don't expose those properties. Does that make sense to you?

[snicoll]

Reviewing the code, I've noticed 3 properties that have a Duration of zero to express the absence of a timeout. This looks really odd to me and I am not keen to bring such a default in auto-completion for our users.

We could fix that by having no default value for those 3 properties (the lack of a timeout value meaning no timeout is something we do elsewhere). And only map the value if it's non-null. I've also created an issue and I'd like some feedback before moving forward.

[snicoll]

This is going to be changed in r2dbc-pool so let's go with the "no default" option for the time being. I'll add a test that will fail as soon as the default changes so that we remember we need to do something about it.