simplify the HTTP API calls

Signed-off-by: Sébastien Boisvert <sebastien.boisvert.3@ulaval.ca>
improve API for actions getMaps, getMapAttributes, getRegions

Signed-off-by: Sébastien Boisvert <sebastien.boisvert.3@ulaval.ca>
improve API calls getSequencesAroundLocation and getSequenceAttributes

Signed-off-by: Sébastien Boisvert <sebastien.boisvert.3@ulaval.ca>
improve action getSequenceAnnotations

Signed-off-by: Sébastien Boisvert <sebastien.boisvert.3@ulaval.ca>
enhance API parameters and responses

Signed-off-by: Sébastien Boisvert <sebastien.boisvert.3@ulaval.ca>