Everywhere: Rename {Deprecated => Byte}String

This commit un-deprecates DeprecatedString, and repurposes it as a byte
string.
As the null state has already been removed, there are no other
particularly hairy blockers in repurposing this type as a byte string
(what it _really_ is).

This commit is auto-generated:
  $ xs=$(ack -l \bDeprecatedString\b\|deprecated_string AK Userland \
    Meta Ports Ladybird Tests Kernel)
  $ perl -pie 's/\bDeprecatedString\b/ByteString/g;
    s/deprecated_string/byte_string/g' $xs
  $ clang-format --style=file -i \
    $(git diff --name-only | grep \.cpp\|\.h)
  $ gn format $(git ls-files '*.gn' '*.gni')

Userland/Libraries/LibGfx/ImageFormats/BMPLoader.cpp

@@ -6,8 +6,8 @@
  */
 
 #include <AK/BuiltinWrappers.h>
+#include <AK/ByteString.h>
 #include <AK/Debug.h>
-#include <AK/DeprecatedString.h>
 #include <AK/Error.h>
 #include <AK/Function.h>
 #include <AK/Try.h>
@@ -82,7 +82,7 @@ template<typename T>
 struct Formatter<Gfx::Endpoint<T>> : Formatter<StringView> {
     ErrorOr<void> format(FormatBuilder& builder, Gfx::Endpoint<T> const& value)
     {
-        return Formatter<StringView>::format(builder, DeprecatedString::formatted("({}, {}, {})", value.x, value.y, value.z));
+        return Formatter<StringView>::format(builder, ByteString::formatted("({}, {}, {})", value.x, value.y, value.z));
     }
 };
 

Userland/Libraries/LibGfx/ImageFormats/DDSLoader.cpp

@@ -622,7 +622,7 @@ void DDSLoadingContext::dump_debug()
         builder.append(" DDS_ALPHA_MODE_CUSTOM"sv);
     builder.append("\n"sv);
 
-    dbgln("{}", builder.to_deprecated_string());
+    dbgln("{}", builder.to_byte_string());
 }
 
 DDSImageDecoderPlugin::DDSImageDecoderPlugin(FixedMemoryStream stream)

Userland/Libraries/LibGfx/ImageFormats/ImageDecoder.cpp

@@ -86,7 +86,7 @@ static OwnPtr<ImageDecoderPlugin> probe_and_sniff_for_appropriate_plugin_with_kn
     return {};
 }
 
-RefPtr<ImageDecoder> ImageDecoder::try_create_for_raw_bytes(ReadonlyBytes bytes, Optional<DeprecatedString> mime_type)
+RefPtr<ImageDecoder> ImageDecoder::try_create_for_raw_bytes(ReadonlyBytes bytes, Optional<ByteString> mime_type)
 {
     if (OwnPtr<ImageDecoderPlugin> plugin = probe_and_sniff_for_appropriate_plugin(bytes); plugin)
         return adopt_ref_if_nonnull(new (nothrow) ImageDecoder(plugin.release_nonnull()));

Userland/Libraries/LibGfx/ImageFormats/ImageDecoder.h

@@ -62,7 +62,7 @@ protected:
 
 class ImageDecoder : public RefCounted<ImageDecoder> {
 public:
-    static RefPtr<ImageDecoder> try_create_for_raw_bytes(ReadonlyBytes, Optional<DeprecatedString> mime_type = {});
+    static RefPtr<ImageDecoder> try_create_for_raw_bytes(ReadonlyBytes, Optional<ByteString> mime_type = {});
     ~ImageDecoder() = default;
 
     IntSize size() const { return m_plugin->size(); }