fix: currentTimeDisplay shows 0:00 after seek

Steps to reproduce originally posted by @johanberonius at
videojs#8988 (comment)

- Pause player
- Click progress bar and hold mouse button down
- Current time display is updated correctly
- Release mouse button
- Current time display is reset to zero
- Play video
- Current time display is updated again

This patch integrates the proposed workaround by @johanberonius, except
for mobile browsers.

The issue was not caused by adding the option
`disableSeekWhileScrubbingOnMobile` per se, but is a side-effect of the
improvements added in 77c99d2.

Caveats:

- On mobiles 0:00 is still visible for an instant on seek before it
  snaps to current time. This can be prevented by setting
  `enableSmoothSeeking`.
- It's possible that the conditional has yet to be tweaked for SVT.

Author: phloxic

src/js/control-bar/progress-control/seek-bar.js

@@ -57,6 +57,9 @@ class SeekBar extends Slider {
 
     this.shouldDisableSeekWhileScrubbing_ = shouldDisableSeekWhileScrubbing;
     this.pendingSeekTime_ = null;
+    if (!IS_IOS && !IS_ANDROID) {
+      this.pendingSeekTime = this.getCurrentTime_;
+    }
 
     this.setEventHandlers_();
   }