Major refractor

- Add regex search and replace
- Add chunk iterator + update line iterator.
- Cleanup/formatting.

include/vase/iterators/line.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "../shard.h"
+#include "chunk.h"
+#include "pch.h"
+
+struct LineIterator {
+  uint32_t offset;
+  ChunkIterator it;
+
+  const char *cursor = nullptr;
+  uint32_t remaining = 0;
+  bool eof = false;
+
+  LineIterator(Shard *r, uint32_t start_line);
+
+  ~LineIterator();
+
+  bool next(std::string &line);
+};