[iOS] Presentation of table views in the leading edge

Adds options to invert the direction of the animation and the position of
the table view when presenting.
Supporting presenting table views in the leading edge is required for the
manual fallback UI: go/leftpresentation

Bug: 845472
Cq-Include-Trybots: luci.chromium.try:ios-simulator-cronet;luci.chromium.try:ios-simulator-full-configs
Change-Id: I1e8466bc90fe29fd77bb71fed1639bcbac14eb02
Reviewed-on: https://chromium-review.googlesource.com/c/1255242
Commit-Queue: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596161}
4 files changed