Fix image component

[cshawaus]

The current image component doesn't work consistently enough and sometimes uses renditions that simply don't exist when viewing the asset in the DAM.

Needs fixing/refinement:

• SVG and GIF support
• Custom rendition maps
• HTL templates have some major variable issues

New features:

• Ability to set default rendition map via template policy
• Add method by which a lazy loading method can be toggled by an author

Misc:

• Remove adaptive image option