[M85] Suppress a macOS hack present in electron to gain webview focus

[M85] Suppress a macOS hack present in electron to gain webview focus

A hack used by electron meant for macOS & extended for other
platforms contingently is causing behavior difference from XWALK.
Since that's the only consumer of 'load-url', removed all
event listeners.
Focus will anyway be gained by WebContents on their respective
show() calls. Fixes P200228-07034 & P200113-07900.

Reference: https://review.tizen.org/gerrit/226898

Change-Id: Ife2e6fd54c146596becd5cd00fb86797a9dc6cae
Signed-off-by: Surya Kumar <surya.kumar7@samsung.com>