Add social media to content blockers

[Rawa]

Implement Social Media content blocker

• We are still missing the strings/translations.

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This change is 

[linear]

DROID-336 Add toggle for social media block list

Just add another DNS content blockers entry for Social media last in the list of content blockers.

The bit to set in the DNS resolver IP is 1 << 5 (0b00100000)

https://mullvad.slack.com/archives/C33N9MLQ7/p1692782875487679

[Pururun]

Reviewed 5 of 5 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved

[albin-mullvad]

Reviewed 5 of 5 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved

[sabercodic]

Reviewable status: 3 of 5 files reviewed, all discussions resolved (waiting on @albin-mullvad and @Pururun)

[Pururun]

Reviewed 2 of 2 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved

[Pururun]

Reviewed 1 of 1 files at r3, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved