[boost-python] Try to fix build issue on Linux

[yurybura]

This PR allows install and use Python3 dependency on Linux and OSX.

Fixes #9824 #9764 #4962

[PhoebeHui]

@yurybura, the CI on linux passed due to 'boost-python:x64-linux=ignore' added to https://github.com/microsoft/vcpkg/blob/master/scripts/ci.baseline.txt#L164, could you please remove it from ci baseline?

[yurybura]

@PhoebeHui boost_modular_build() doesn't configure Python on Linux. Let me try to fix it first. Please add WIP label for this PR. Thanks.

[PhoebeHui]

@yurybura, added, thanks for taking look at this issue!

[yurybura]

Dear @PhoebeHui, could you start reviewing of this PR? I have just finished fixing this issue.

I think Boost's CMake scripts should be reworked to merge in one for all platforms in separate PR...

[yurybura]

Build bot has failed but this fail isn't related to my changes... CI quite unstable again.

[adamvm]

@yurybura ready :) I tested after git pull and ./vcpkg install boost including boost-python finished successfully. Thank you

[yurybura]

@adamvm Thank you.
@PhoebeHui Please start review of this PR.

[PhoebeHui]

@yurybura, thanks for the updates!

[PhoebeHui]

@ras0219-msft, could you help review?

[PhoebeHui]

LGTM

[zlojvavan]

how to apply the fix?

[PhoebeHui]

@ras0219-msft, could you priority to review this PR?

[yurybura]

@PhoebeHui, @strega-nil, @ras0219-msft
Ping. Please have a look this PR.

[strega-nil]

I'm happy with this! Thanks @yurybura, this is really awesome :)

[cenit]

Hi! Thanks for the PR, but... boost-python was broken on Linux but still is... at least for me.
Installing the python3 dependency fails with an error message telling the dev that to build out of tree the source must be clean (at install phase). Of course, buildtrees folder was removed before installing.

[yurybura]

@cenit, looks like it is a python3 port issue. Could you report a separate bug report for this?