TEST: Capsule test for class and CD

See merge request iMSTK/iMSTK!769

COMP: Improve source download strategy for Assimp project

See merge request iMSTK/iMSTK!770

This commit partially reverts ce3d6a91d (Convert external projects to zips)

It avoids check-sum verification failure in the following scenarios:

- the branch with the patches is updated to include additional patches.

- the git server re-generate the cached archives with a new approach
  leading to different checksums.
  see [1], [2] and [3] for discussion of similar issues with eiter GitLab
  or GitHub

It also references the branch imstk-v3.3.1-2016-07-08-a8673d482 (equivalent
to fixCompilationError). The associated naming convention is documented
at https://gitlab.kitware.com/iMSTK/assimp/-/blob/welcome/README.md

[1] Gitlab release tarball stability
    https://forum.gitlab.com/t/gitlab-release-tarball-stability/41888

[2] Why are the md5 checksums for download archives different?
    https://forum.gitlab.com/t/why-are-the-md5-checksums-for-download-archives-different/41649/2

[3] Github Archive URL checksums have changed
    https://github.com/spack/spack/issues/5411

DOC: Add CD support matrix

See merge request iMSTK/iMSTK!768

COMP: Consistent case in filenames

See merge request iMSTK/iMSTK!766

ENH: Critical damping for RigidObjectController

See merge request iMSTK/iMSTK!764

REFAC: Adjust & improve virtual coupling in examples, group rendering examples, PBDCutting & PBDPicking put in PBD group

DOC: Include dashboard link in readme, update PbdModel code example

See merge request iMSTK/iMSTK!763

REFAC: Remove sphFemPbdExample

See merge request iMSTK/iMSTK!756

BUG: Swig fixes

See merge request iMSTK/iMSTK!761

ENH: Add VRPN to swig wrappings

See merge request iMSTK/iMSTK!759

BUG: Fix haptics in static suture example

See merge request iMSTK/iMSTK!762

ENH: Adds mouse controls for static suture example

See merge request iMSTK/iMSTK!757

ENH: Adds getters for spring force, damper force, & getForce is now getDeviceForce

See merge request iMSTK/iMSTK!758

COMP: Fix compilation failure after previous refactor

See merge request iMSTK/iMSTK!755