GF-54909: Fixed bug with jumpForward not working properly.

Issue
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After the `Video` control is initialized, if the `jumpSec` value is set to a number in string format, the `jumpForward` method no longer works.

Fix
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The `jumpForward` method is expecting `jumpSec` as an integer, but it is not uncommon for `jumpSec` to be passed in as a string, if it is being derived from an input field. We now run `parseInt` on `jumpSec` when jumping forward.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>