Add Hireable and Website columns to the main grid in DevIndex.

• Hireable: Boolean icon column. Position near generic icon/link columns.
• Website: Link column.
• Create generic Neo.component.Icon and Neo.grid.column.Icon to support these and future icon-based columns efficiently (pooling).
• Create generic Neo.component.IconLink and Neo.grid.column.IconLink to support these and future icon-link-based columns efficiently (pooling).
• Refactor existing icon columns (like LinkedIn) to use the new generic implementation if applicable.
• The new components need their own scss files and support for the neo-dark and neo-light theme based on theme variables. Avoid inline styles.