feat!: decouple download and scaffold from main package into workspace

Added workspace structure to Cargo.toml. This way we don't need to build
all dependencies for helper binaries. Also changed .cargo/config
accordingly.

.cargo/config

@@ -1,6 +1,4 @@
 [alias]
-scaffold = "run --bin scaffold --quiet --release --"
-download = "run --bin download --quiet --release --"
-download_all = "run --bin download_all --quiet --release --"
-
-solve = "run --bin"
+scaffold = "run -p scaffold --release --"
+download = "run -p download --release --"
+solve = "run --bin --release"