Picture tag for DAM rendition is not accordance with W3C validator

Requirement

Generated picture tag with source tags should be accordance with W3C markup validation (validator.w3.org)

Code details

Backend code:

Generated code:

Step to reproduce

1. Add component configured as above.
2. Publish page
3. Copy page markup and paste in W3C validator

Actual behaviour

There are 2 errors

• Stray end tag source.

• When the srcset attribute has any image candidate string with a width descriptor, the sizes attribute must also be present.