Merge branch 'enh/imagetree' into 'master'

.ci/test_template.sh

.gitlab-ci.yml

CHANGELOG.rst

doc/fsl.utils.filetree.query.rst

doc/fsl.utils.filetree.rst

fsl/data/mesh.py

fsl/utils/filetree/__init__.py

fsl/utils/filetree/filetree.py

fsl/utils/filetree/parse.py

fsl/utils/filetree/query.py

fsl/utils/filetree/utils.py

fsl/utils/path.py

tests/test_filetree/__init__.py

tests/test_filetree/test_query.py

tests/test_fsl_utils_path.py