Add new allowed_types option to legacy_objc_type rule

[kapitoshka438]

This PR adds a new option to allow certain types, particularly when they are required by third-party dependencies.
#3723 (comment)

[SwiftLintBot]

	18 Messages
📖	Building this branch resulted in a binary size of 29602.77 KiB vs 29581.29 KiB when built on main (0% larger).
📖	Linting Aerial with this PR took 1.66 s vs 0.95 s on main (74% slower).
📖	Linting Alamofire with this PR took 1.3 s vs 1.29 s on main (0% slower).
📖	Linting Brave with this PR took 8.68 s vs 8.66 s on main (0% slower).
📖	Linting DuckDuckGo with this PR took 5.84 s vs 5.82 s on main (0% slower).
📖	Linting Firefox with this PR took 11.92 s vs 11.95 s on main (0% faster).
📖	Linting Kickstarter with this PR took 10.01 s vs 9.99 s on main (0% slower).
📖	Linting Moya with this PR took 0.54 s vs 0.53 s on main (1% slower).
📖	Linting NetNewsWire with this PR took 2.91 s vs 2.9 s on main (0% slower).
📖	Linting Nimble with this PR took 0.78 s vs 0.81 s on main (3% faster).
📖	Linting PocketCasts with this PR took 8.92 s vs 8.61 s on main (3% slower).
📖	Linting Quick with this PR took 0.45 s vs 0.43 s on main (4% slower).
📖	Linting Realm with this PR took 4.61 s vs 4.59 s on main (0% slower).
📖	Linting Sourcery with this PR took 2.37 s vs 2.35 s on main (0% slower).
📖	Linting Swift with this PR took 4.84 s vs 4.81 s on main (0% slower).
📖	Linting VLC with this PR took 1.32 s vs 1.33 s on main (0% faster).
📖	Linting Wire with this PR took 18.91 s vs 18.83 s on main (0% slower).
📖	Linting WordPress with this PR took 11.5 s vs 11.47 s on main (0% slower).

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