Add HTTP content-type for WebP and AVIF (#229)

* Add HTTP content-type for WebP and AVIF

This PR extends the _setContentTypeFromPath method to correctly identify and assign Content-Type headers for .webp (image/webp) and .avif (image/avif) files. Additionally, all HTTP headers are now formatted in Title Case, aligning with RFC 7231 and improving consistency across responses.

Developers are encouraged to adopt AVIF or WebP formats over legacy image types such as GIF, PNG, or JPEG. Both formats are fully supported by all major modern browsers and typically offer significant file size reductions (often 50% or more) without perceptible quality loss.

Conversion of assets is straightforward using tools like squoosh.app (free and online), which supports batch optimization and visual comparisons across formats.

* ci(pre-commit): Apply automatic fixes

* revert Title Case changes in literals.h

me-no-dev requests fulfilled:
- please do not change the styling
- to split it in two PRs

---------

Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>

Author: JosePineiro

src/WebResponses.cpp

@@ -662,6 +662,10 @@ void AsyncFileResponse::_setContentTypeFromPath(const String &path) {
     _contentType = T_image_svg_xml;
   } else if (strcmp(dot, T__jpg) == 0) {
     _contentType = T_image_jpeg;
+  } else if (strcmp(dot, T__webp) == 0) {
+    _contentType = T_image_webp;
+  } else if (strcmp(dot, T__avif) == 0) {
+    _contentType = T_image_avif;
   } else if (strcmp(dot, T__gif) == 0) {
     _contentType = T_image_gif;
   } else if (strcmp(dot, T__woff2) == 0) {

src/literals.h

@@ -106,6 +106,7 @@ static constexpr const char *T_RCT_EVENT = "RCT_EVENT";
 static constexpr const char *T_ERROR = "ERROR";
 
 // extensions & MIME-Types
+static constexpr const char *T__avif = ".avif";
 static constexpr const char *T__css = ".css";
 static constexpr const char *T__eot = ".eot";
 static constexpr const char *T__gif = ".gif";
@@ -120,6 +121,7 @@ static constexpr const char *T__pdf = ".pdf";
 static constexpr const char *T__png = ".png";
 static constexpr const char *T__svg = ".svg";
 static constexpr const char *T__ttf = ".ttf";
+static constexpr const char *T__webp = ".webp";
 static constexpr const char *T__woff = ".woff";
 static constexpr const char *T__woff2 = ".woff2";
 static constexpr const char *T__xml = ".xml";
@@ -134,10 +136,12 @@ static constexpr const char *T_font_eot = "font/eot";
 static constexpr const char *T_font_ttf = "font/ttf";
 static constexpr const char *T_font_woff = "font/woff";
 static constexpr const char *T_font_woff2 = "font/woff2";
+static constexpr const char *T_image_avif = "image/avif";
 static constexpr const char *T_image_gif = "image/gif";
 static constexpr const char *T_image_jpeg = "image/jpeg";
 static constexpr const char *T_image_png = "image/png";
 static constexpr const char *T_image_svg_xml = "image/svg+xml";
+static constexpr const char *T_image_webp = "image/webp";
 static constexpr const char *T_image_x_icon = "image/x-icon";
 static constexpr const char *T_text_css = "text/css";
 static constexpr const char *T_text_event_stream = "text/event-stream";