feat: add cJSON and SQLite amalgamation source files under deps/

Add the cJSON library (cJSON.c, cJSON.h) and SQLite amalgamation
(sqlite3.c, sqlite3.h, sqlite3ext.h, shell.c) as vendored dependencies
in the deps/ directory for use by the project build system.

test/jinja/whitespace.wren

@@ -0,0 +1,15 @@
+// retoor <retoor@molodetz.nl>
+
+import "jinja" for Environment, DictLoader
+
+var env = Environment.new(DictLoader.new({
+  "trim_left": "x  {{- y }}",
+  "trim_right": "{{ y -}}  x",
+  "trim_both": "x  {{- y -}}  x",
+  "block_trim": "x  {\%- if true \%}y{\% endif -\%}  x"
+}))
+
+System.print(env.getTemplate("trim_left").render({"y": "Y"})) // expect: xY
+System.print(env.getTemplate("trim_right").render({"y": "Y"})) // expect: Yx
+System.print(env.getTemplate("trim_both").render({"y": "Y"})) // expect: xYx
+System.print(env.getTemplate("block_trim").render({})) // expect: xyx