[ios][STG] Intercept URL for data sharing

This CL
1. initializes DataSharingUIDelegateIOS and DataSharingSDKDelegateIOS
and passes them to DataSharingServiceImpl
2. adds DataSharingTabHelper to observe the navigation per web state
3. intercepts the navigation and calls
HandleShareURLNavigationIntercepted() when the URL is for data
sharing (defined in kDataSharingFeature and its feature param
kDataSharingURL)

added in a follow-up CL.

Bug: 361249212
Low-Coverage-Reason: New logic is behind the flag. The test will be
Change-Id: I59b8818a4f393d8885044f9a90a7929ad6d26bf6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5830884


Reviewed-by: Siddhartha S <ssid@chromium.org>
Commit-Queue: Asami Doi <asamidoi@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1350697}