missing deps + clean apt files

Author: prince-chrismc

.devcontainer/Dockerfile

@@ -1,8 +1,17 @@
 FROM ubuntu:22.04
 
 RUN export DEBIAN_FRONTEND=noninteractive \
-    && apt-get update \
-    && apt-get -y install git g++ cmake libssl-dev \
-       libgtest-dev clang-format clang-tidy doxygen
+    && apt-get update && apt-get -y install \
+    clang++ \
+    clang-format \
+    clang-tidy \
+    cmake \
+    doxygen \
+    graphviz \
+    git \
+    g++ \
+    libssl-dev \
+    libgtest-dev \
+    && rm -rf /var/lib/apt/lists/*
 
 ENV CMAKE_CXX_CLANG_TIDY="clang-tidy;-fix"