Align platform versions in SPM manifest and Xcode project

[calvincestari]

This PR:

1. Adds platform versions to the SPM manifest; we discovered this was missing while debugging Update SQLite.swift to version 13.1 apollographql/apollo-ios#2015. This addition should allow SPM to correctly resolve deployment targets.
2. Moves the Xcode deployment versions configuration from each target to the project level. There is some personal preference to this change but I do also believe there is value in being able to set all deployment versions in one place (project) vs. the individual targets where it's easy to miss versions not being the same. I also changed the tvOS target to match Cocoapods, which specifies 9.1.

I saw that #1083 already attempted this but that PR seems dead and the fork has also been deleted. If this one is merged you can close #1083.

Question:

1. Is there any particular reason why SQLite.swift 0.13.0 bumped the macOS deployment target to 10.15? It seems at odds with the iOS deployment target of 9.0 which would have greater support for older APIs.

[jberkel]

Thanks for the PR, tests are failing. Regarding MacOS 10.15, I'm not sure, I see it was changed in #1051. Perhaps it can be reverted.

[calvincestari]

Thanks for merging that @jberkel!

@nathanfallet it looks like you made the change to the macOS version in the 0.13.0 release. I've built the project using the 'SQLite Mac' scheme with macOS deployment target 10.15 down back to 10.10 and I don't get any warnings; do you recall any specifics of that particular change?

[jberkel]

Seems to work fine on the CI with 10.10. If nobody objects, we can just set it back before making the next release. The problem is of course testing this on actual 10.10 systems.

[nathanfallet]

@calvincestari You're right, I changed the deployment target instead of the base SDK. Sorry for that mistake.

[jberkel]

@nathanfallet ok, I reverted it. It's probably worth doing a new release with the current master soon, can you take charge of it?

[calvincestari]

Hey @nathanfallet, no need to apologize. Thanks for the change both of you, I'm looking forward to getting our users onto the latest version.