fix(FEC-9433): timer on seek preview displayed as NaN:NaN:NaN

[RoyBregman]

Description of the Changes

when dragging scrubber to 0 it fell back to e.changedTouches which was undefined.
Changed the logic to first use e.clientX if is a number (zero included)

Fixes FEC-9433

CheckLists

• changes have been done against master branch, and PR does not conflict
• new unit / functional tests have been added (whenever applicable)
• test are passing in local environment
• Travis tests are passing (or test results are not worse than on master branch :))
• Docs have been updated

[OrenMe]

@RoyBregman what happens when you scrub all the way to the end(right side)?

[RoyBregman]

@RoyBregman what happens when you scrub all the way to the end(right side)?

It will work as today - The "bug" was only that clientx was ignored when 0 when actually 0 is okay
I rewrote it again with Yair, maybe now it is more readable