fix ITK easyconfigs: switch to CMakePythonPackage easyblock, also enable -DITK_USE_SYSTEM_HDF5 configuration option, fix download URLs

[Flamefire]

(created using eb --new-pr)

Having trouble with the ITK ECs. Major issue and workaround was to add LC_ALL=C to prebuildopts and using explicit "system" deps, i.e. dependencies installed via EasyBuild.

• fix some URLs (outdated/moved -.-)
• remove -DCMAKE_BUILD_TYPE
• use build_shared_libs
• don't use l as a local variable
• Use CMakePythonPackage as ITK is a prime example for that (no need to manually set PYTONPATH etc)

Requires:

• reset runtest to None in CMakePythonPackage easybuild-easyblocks#2536

[Flamefire]

Test report by @Flamefire
Using easyblocks from PR(s) easybuilders/easybuild-easyblocks#2536
SUCCESS
Build succeeded for 1 out of 1 (1 easyconfigs in total)
taurusi6606.taurus.hrsk.tu-dresden.de - Linux RHEL 7.9, x86_64, Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (haswell), Python 2.7.5
See https://gist.github.com/a4716faa64ea1503ad432875cdfb2182 for a full test report.

[Flamefire]

Test report by @Flamefire
Using easyblocks from PR(s) easybuilders/easybuild-easyblocks#2536
SUCCESS
Build succeeded for 19 out of 19 (14 easyconfigs in total)
taurusi6459.taurus.hrsk.tu-dresden.de - Linux RHEL 7.9, x86_64, Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (haswell), Python 2.7.5
See https://gist.github.com/0c11ce4fed461ac485eca9ddbce80ea4 for a full test report.

[boegel]

Test report by @boegel
SUCCESS
Build succeeded for 14 out of 14 (14 easyconfigs in total)
node2641.swalot.os - Linux centos linux 7.9.2009, x86_64, Intel(R) Xeon(R) CPU E5-2660 v3 @ 2.60GHz (haswell), Python 3.6.8
See https://gist.github.com/d5542907c1cec9317cef34a5dea18816 for a full test report.

[boegel]

lgtm

[boegel]

Going in, thanks @Flamefire!