Support replacing ROS package path by command line

[taiki-e]

• Support replacing ROS package path to URL/path (--package-path option on native, package-path[] URL parameter on web). This allows the processing of ROS packages on systems where ROS is not installed, such as the web.
• Support http/https for URDF path on native. This has already been supported for URDF path on web, and for mesh path on both native and web.

Examples

native:

cargo run -- https://raw.githubusercontent.com/ToyotaResearchInstitute/hsr_description/master/robots/hsrb4s.obj.urdf --package-path hsr_meshes=https://raw.githubusercontent.com/ToyotaResearchInstitute/hsr_meshes/master

web:

http://localhost:8080/?urdf=https://raw.githubusercontent.com/ToyotaResearchInstitute/hsr_description/master/robots/hsrb4s.obj.urdf&package-path[]=hsr_meshes=https://raw.githubusercontent.com/ToyotaResearchInstitute/hsr_meshes/master

[OTL]

LGTM.