Merge branch 'feature/add-oembed-parser' into 'develop'

Add OEmbed parser

See merge request !661
2 jobs for develop in 1 minute and 52 seconds (queued for 9 seconds)
Name Stage Failure
failed
unit-testing Test
== Compilation error in file test/plugs/session_authentication_plug_test.exs ==
** (CompileError) test/plugs/session_authentication_plug_test.exs:22: Pleroma.User.__struct__/1 is undefined, cannot expand struct Pleroma.User
(stdlib) lists.erl:1354: :lists.mapfoldl/3
(stdlib) lists.erl:1355: :lists.mapfoldl/3
(elixir) expanding macro: Kernel.|>/2
test/plugs/session_authentication_plug_test.exs:22: Pleroma.Plugs.SessionAuthenticationPlugTest.__ex_unit_setup_1/1
(elixir) lib/code.ex:767: Code.require_file/2
(elixir) lib/kernel/parallel_compiler.ex:209: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/6
ERROR: Job failed: exit code 1