Add support for a "_pretty" meta-parameter on all REST controllers which instructs WordPress to return pretty-printed JSON, for better readability when inspecting endpoint responses in curl output or certain developer tools.
Introduce the "rest_json_encode_options" filter to permit site owners to control this behavior globally.
Props Viper007Bond, TimothyBlynJacobs, chrisguitarguy, johnbillion, swissspidy, adamsilverstein, danielbachhuber, rmccue.
Fixes#41998.
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