refactor(postgres) improve postgres code base (#20808)

Co-authored-by: cirospaciari <6379399+cirospaciari@users.noreply.github.com>

src/sql/postgres/protocol/ArrayList.zig

@@ -0,0 +1,22 @@
+array: *std.ArrayList(u8),
+
+pub fn offset(this: @This()) usize {
+    return this.array.items.len;
+}
+
+pub fn write(this: @This(), bytes: []const u8) AnyPostgresError!void {
+    try this.array.appendSlice(bytes);
+}
+
+pub fn pwrite(this: @This(), bytes: []const u8, i: usize) AnyPostgresError!void {
+    @memcpy(this.array.items[i..][0..bytes.len], bytes);
+}
+
+pub const Writer = NewWriter(@This());
+
+// @sortImports
+
+const ArrayList = @This();
+const std = @import("std");
+const AnyPostgresError = @import("../AnyPostgresError.zig").AnyPostgresError;
+const NewWriter = @import("./NewWriter.zig").NewWriter;