Add Akamai Image and Video Manager image provider support

[stefashkaa]

Feature Title

Add Akamai Image and Video Manager image provider support

Description

Add an Akamai Image and Video Manager provider focused on derivative selection through width, density, and configured image policies.

Use Case

A site with Akamai image policies configured needs responsive image requests while allowing the service to apply its policy-defined crop and quality settings.

Proposed Solution

• Add and export akamai through the core provider registry so Angular, React, and Svelte can use the shared configuration.
• Map documented width, density, and policy options to imwidth, imdensity, and impolicy while preserving the origin URL and unrelated parameters.
• Document that requested widths can resolve to configured policy breakpoints. Keep quality and crop controls within the policy contract unless a direct API mapping is verified.
• Do not map core output format to imformat: that parameter denotes a browser profile. Define restrictions for explicit picture formats and verify density handling against core’s responsive sizing to prevent double scaling.
• Add setup documentation and focused fixtures covering policy preservation, breakpoint behavior, density scaling, and unsupported direct quality/format controls. Validate advertised dimensions and content types against an enabled service or controlled server where applicable.

Alternatives Considered

Append Akamai derivative parameters manually or use a custom provider. Policies remain part of Akamai configuration regardless of how the URL is generated.

Examples from Other Libraries

• Not found
• Select a specific derivative
• Test images on demand
• Image Manager width override