Setting optimised background image src

[anuj-adobe]

Updated two blocks -

1. Hero-Slider: Changed DOM Structure and logic to show background. Earlier background img src was explicitly set via js on block's parent DIV. Now, banner-imgs have been moved under the parent DIV occupying 100% width and their visibility is controlled via '.active' class.
2. Accordion Block: The background img of collapsed item is set using new method getOptimalImageFromPictureTag() which takes picture element as input and returns the web optimal img src by matching the media.

Fix #62

Test URLs:

• Before: https://main--infosys--aemsites.hlx.live/iki
• After: https://issue-62--infosys--aemsites.hlx.live/iki

[aem-code-sync[bot]]

Hello, I'm the AEM Code Sync Bot and I will run some actions to deploy your branch and validate page speed. In case there are problems, just click a checkbox below to rerun the respective action.

• [ ] Re-run PSI checks
• [ ] Re-sync branch

Commits

* [1836367](https://github.com/aemsites/infosys/commit/1836367e4f0021e6ecd3ee85f187e2397942882c) :white_check_mark: (latest) * [e549a46](https://github.com/aemsites/infosys/commit/e549a463b301188120ca4a4cc42f4c0659620e1d) :white_check_mark: * [4540853](https://github.com/aemsites/infosys/commit/4540853300c5068a1737c9486e6f0be731757452) :white_check_mark: * [454378f](https://github.com/aemsites/infosys/commit/454378ff9d63eb3d7efcf18e4b5aa1f779634074) :white_check_mark: * [8febc31](https://github.com/aemsites/infosys/commit/8febc31c306a1df25fec860bddb4731176045fd9) :white_check_mark: * [ccce8ea](https://github.com/aemsites/infosys/commit/ccce8ea76583a2609d039743091dcbfae9aeb655) :white_check_mark:

[aem-code-sync[bot]]

Page	Scores	Audits	Google
/iki