feat: Add central logging pragma (#843)

## Summary

* Definition and use of a central LOG function, that can later be
extended or completely be removed (for public use where debugging
information may not be required) to save flash by suppressing the
-DENABLE_SERIAL_LOG like in the slim branch

* **What changes are included?**

## Additional Context
* By using the central logger the usual:
```
#include <HardwareSerial.h>
...
  Serial.printf("[%lu] [WCS] Obfuscating/deobfuscating %zu bytes\n", millis(), data.size());
```
would then become
```
#include <Logging.h>
...
  LOG_DBG("WCS", "Obfuscating/deobfuscating %zu bytes", data.size());
```
You do have ``LOG_DBG`` for debug messages, ``LOG_ERR`` for error
messages and ``LOG_INF`` for informational messages. Depending on the
verbosity level defined (see below) soe of these message types will be
suppressed/not-compiled.

* The normal compilation (default) will create a firmware.elf file of
42.194.356 bytes, the same code via slim will create 42.024.048 bytes -
170.308 bytes less
* Firmware.bin : 6.469.984 bytes for default, 6.418.672 bytes for slim -
51.312 bytes less


### AI Usage

While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.

Did you use AI tools to help write this code? _NO_

---------

Co-authored-by: Xuan Son Nguyen <son@huggingface.co>

lib/Epub/Epub/parsers/ChapterHtmlSlimParser.cpp

@@ -2,7 +2,7 @@
 
 #include <GfxRenderer.h>
 #include <HalStorage.h>
-#include <HardwareSerial.h>
+#include <Logging.h>
 #include <expat.h>
 
 #include "../Page.h"
@@ -168,7 +168,7 @@ void XMLCALL ChapterHtmlSlimParser::startElement(void* userData, const XML_Char*
       }
     }
 
-    Serial.printf("[%lu] [EHP] Image alt: %s\n", millis(), alt.c_str());
+    LOG_DBG("EHP", "Image alt: %s", alt.c_str());
 
     self->startNewTextBlock(centeredBlockStyle);
     self->italicUntilDepth = min(self->italicUntilDepth, self->depth);
@@ -386,7 +386,7 @@ void XMLCALL ChapterHtmlSlimParser::characterData(void* userData, const XML_Char
   // memory.
   // Spotted when reading Intermezzo, there are some really long text blocks in there.
   if (self->currentTextBlock->size() > 750) {
-    Serial.printf("[%lu] [EHP] Text block too long, splitting into multiple pages\n", millis());
+    LOG_DBG("EHP", "Text block too long, splitting into multiple pages");
     self->currentTextBlock->layoutAndExtractLines(
         self->renderer, self->fontId, self->viewportWidth,
         [self](const std::shared_ptr<TextBlock>& textBlock) { self->addLineToPage(textBlock); }, false);
@@ -477,7 +477,7 @@ bool ChapterHtmlSlimParser::parseAndBuildPages() {
   int done;
 
   if (!parser) {
-    Serial.printf("[%lu] [EHP] Couldn't allocate memory for parser\n", millis());
+    LOG_ERR("EHP", "Couldn't allocate memory for parser");
     return false;
   }
 
@@ -499,7 +499,7 @@ bool ChapterHtmlSlimParser::parseAndBuildPages() {
   do {
     void* const buf = XML_GetBuffer(parser, 1024);
     if (!buf) {
-      Serial.printf("[%lu] [EHP] Couldn't allocate memory for buffer\n", millis());
+      LOG_ERR("EHP", "Couldn't allocate memory for buffer");
       XML_StopParser(parser, XML_FALSE);                // Stop any pending processing
       XML_SetElementHandler(parser, nullptr, nullptr);  // Clear callbacks
       XML_SetCharacterDataHandler(parser, nullptr);
@@ -511,7 +511,7 @@ bool ChapterHtmlSlimParser::parseAndBuildPages() {
     const size_t len = file.read(buf, 1024);
 
     if (len == 0 && file.available() > 0) {
-      Serial.printf("[%lu] [EHP] File read error\n", millis());
+      LOG_ERR("EHP", "File read error");
       XML_StopParser(parser, XML_FALSE);                // Stop any pending processing
       XML_SetElementHandler(parser, nullptr, nullptr);  // Clear callbacks
       XML_SetCharacterDataHandler(parser, nullptr);
@@ -523,8 +523,8 @@ bool ChapterHtmlSlimParser::parseAndBuildPages() {
     done = file.available() == 0;
 
     if (XML_ParseBuffer(parser, static_cast<int>(len), done) == XML_STATUS_ERROR) {
-      Serial.printf("[%lu] [EHP] Parse error at line %lu:\n%s\n", millis(), XML_GetCurrentLineNumber(parser),
-                    XML_ErrorString(XML_GetErrorCode(parser)));
+      LOG_ERR("EHP", "Parse error at line %lu:\n%s", XML_GetCurrentLineNumber(parser),
+              XML_ErrorString(XML_GetErrorCode(parser)));
       XML_StopParser(parser, XML_FALSE);                // Stop any pending processing
       XML_SetElementHandler(parser, nullptr, nullptr);  // Clear callbacks
       XML_SetCharacterDataHandler(parser, nullptr);
@@ -568,7 +568,7 @@ void ChapterHtmlSlimParser::addLineToPage(std::shared_ptr<TextBlock> line) {
 
 void ChapterHtmlSlimParser::makePages() {
   if (!currentTextBlock) {
-    Serial.printf("[%lu] [EHP] !! No text block to make pages for !!\n", millis());
+    LOG_ERR("EHP", "!! No text block to make pages for !!");
     return;
   }