Make format sniffers initialization public (#628)

Author: grighakobian

Sources/Shared/Toolkit/Format/Sniffers/AudioFormatSniffer.swift

@@ -8,6 +8,8 @@ import Foundation
 
 /// Sniffs audio formats.
 public class AudioFormatSniffer: FormatSniffer {
+    public init() {}
+
     public func sniffHints(_ hints: FormatHints) -> Format? {
         if hints.hasFileExtension("aac") || hints.hasMediaType("audio/aac") {
             return Format(specifications: .aac, mediaType: .aac, fileExtension: "aac")

Sources/Shared/Toolkit/Format/Sniffers/BitmapFormatSniffer.swift

@@ -8,6 +8,8 @@ import Foundation
 
 /// Sniffs bitmap formats.
 public class BitmapFormatSniffer: FormatSniffer {
+    public init() {}
+
     public func sniffHints(_ hints: FormatHints) -> Format? {
         if hints.hasFileExtension("avif", "avifs") || hints.hasMediaType("image/avif") {
             return Format(specifications: .avif, mediaType: .avif, fileExtension: "avif")

Sources/Shared/Toolkit/Format/Sniffers/HTMLFormatSniffer.swift

@@ -8,6 +8,8 @@ import Foundation
 
 /// Sniffs an HTML or XHTML document.
 public struct HTMLFormatSniffer: FormatSniffer {
+    public init() {}
+
     public func sniffHints(_ hints: FormatHints) -> Format? {
         if
             hints.hasFileExtension("htm", "html") ||

Sources/Shared/Toolkit/Format/Sniffers/JSONFormatSniffer.swift

@@ -8,6 +8,8 @@ import Foundation
 
 /// Sniffs a JSON document.
 public struct JSONFormatSniffer: FormatSniffer {
+    public init() {}
+
     public func sniffHints(_ hints: FormatHints) -> Format? {
         if
             hints.hasFileExtension("json") ||

Sources/Shared/Toolkit/Format/Sniffers/LCPLicenseFormatSniffer.swift

@@ -8,6 +8,8 @@ import Foundation
 
 /// Sniffs an LCP License Document.
 public struct LCPLicenseFormatSniffer: FormatSniffer {
+    public init() {}
+
     public func sniffHints(_ hints: FormatHints) -> Format? {
         if
             hints.hasFileExtension("lcpl") ||

Sources/Shared/Toolkit/Format/Sniffers/LanguageFormatSniffer.swift

@@ -7,6 +7,8 @@
 import Foundation
 
 public class LanguageFormatSniffer: FormatSniffer {
+    public init() {}
+
     public func sniffHints(_ hints: FormatHints) -> Format? {
         // JavaScript
         if

Sources/Shared/Toolkit/Format/Sniffers/OPDSFormatSniffer.swift

@@ -8,6 +8,8 @@ import Foundation
 
 /// Sniffs OPDS documents.
 public class OPDSFormatSniffer: FormatSniffer {
+    public init() {}
+
     public func sniffHints(_ hints: FormatHints) -> Format? {
         if hints.hasMediaType("application/atom+xml;type=entry;profile=opds-catalog") {
             return opds1Entry

Sources/Shared/Toolkit/Format/Sniffers/PDFFormatSniffer.swift

@@ -10,6 +10,8 @@ import Foundation
 ///
 /// Reference: https://www.loc.gov/preservation/digital/formats/fdd/fdd000123.shtml
 public struct PDFFormatSniffer: FormatSniffer {
+    public init() {}
+
     public func sniffHints(_ hints: FormatHints) -> Format? {
         if
             hints.hasFileExtension("pdf") ||

Sources/Shared/Toolkit/Format/Sniffers/RARFormatSniffer.swift

@@ -8,6 +8,8 @@ import Foundation
 
 /// Sniffs a RAR file.
 public struct RARFormatSniffer: FormatSniffer {
+    public init() {}
+
     public func sniffHints(_ hints: FormatHints) -> Format? {
         if
             hints.hasFileExtension("rar") ||

Sources/Shared/Toolkit/Format/Sniffers/RPFFormatSniffer.swift

@@ -8,6 +8,8 @@ import Foundation
 
 /// Sniffs a Readium Web Publication package.
 public struct RPFFormatSniffer: FormatSniffer {
+    public init() {}
+
     public func sniffHints(_ hints: FormatHints) -> Format? {
         if hints.hasMediaType("application/audiobook+zip") || hints.hasFileExtension("audiobook") {
             return audiobook