Proposed build wrapper script for static libs macOS / iOS / Android platforms

[andybrucenet]

We wish to integrate kyber and other algorithms in our apps via oqs-provider - and this requires a built liboqs foreach of our cross-compiled solutions in addition to a built openssl.

The script has the following features:

• CMake output for all platforms (e.g. build/apple/iphoneos/arm64 or build/android/arm64-v8a).
• The script can also generate build/export in a versioned format; example: build/export/android/0.10.0-dev/armeabi-v7a/lib.
• The export version is determined automatically from the cmake-generated headers.
• Because the cmake-generated headers are platform specific via #defines the output includes headers for each platform. Example: build/export/apple/0.10.0-dev/macosx/arm64/include
• Libraries are always built static and macOS / iOS libraries include all required architectures.
• Script can be invoked with any of the included functions; by default, builds all platforms and creates export output.

The output from the script can be used as-is with the analogous script for the oqs-provider project - there is a separate PR for that project.

No

No new features added. The script requires access to a versioned openssl with subfolders to each platform.
Examples:

• Android - [dir]/android/3.2.1 with subfolders similar to arm64-v8a/{include,lib}
• Apple - [dir]/apple/3.2.1 with subfolders similar to iphoneos/{include,lib}

• [NO] Does this PR change the input/output behaviour of a cryptographic algorithm (i.e., does it change known answer test values)? (If so, a version bump will be required from x.y.z to x.(y+1).0.)
• [NO] Does this PR change the list of algorithms available -- either adding, removing, or renaming? Does this PR otherwise change an API? (If so, PRs in fully supported downstream projects dependent on these, i.e., oqs-provider and OQS-OpenSSH will also need to be ready for review and merge by the time this is merged.)

[baentsch]

Suggest to close as per open-quantum-safe/oqs-provider#363 (comment). Tagging @dstebila @andybrucenet for additional feedback.

[SWilson4]

Closing, cf. open-quantum-safe/oqs-provider#363 (comment)