[M108 Migration][MM] Manage multi-players using resource conflict callback.

[M108 Migration][MM] Manage multi-players using resource conflict callback.

Because of hw decoder capacity, only one player can be played on the web page
including multi-players.
It is not known which player will play after web page loading.
Thereafter, the player requested by the user plays, and the other player
is suspended.

- Players who receive the ResourceConflict callback from Resource Manager
  should be suspended.
- Seek is pended while reconfiguring pipeline during resume.
  After prepare, request demuxer seek to operate the seek normally.

Reference:
https://review.tizen.org/gerrit/283009

Change-Id: I4686502216cc1ba266f0f95d01baf7a9a5abc757
Signed-off-by: Sun-woo Nam <sunny.nam@samsung.com>
Signed-off-by: Suhaspoornachandra <s.poornachan@samsung.com>