resolc crate (#328)

- Factor the YUL crate out of `revive-solidity`.
- `revive-solidity` is in reality not a Solidity implementation but the
revive solidity compiler driver (`resolc`). By renaming we not only get
this straight but also a binary with the same name as the crate which
should be less confusing.

---------

Signed-off-by: Cyrill Leutwiler <bigcyrill@hotmail.com>

crates/resolc/src/process/output.rs

@@ -0,0 +1,21 @@
+//! Process for compiling a single compilation unit.
+//! The output data.
+
+use serde::Deserialize;
+use serde::Serialize;
+
+use crate::build::contract::Contract as ContractBuild;
+
+/// The output data.
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Output {
+    /// The contract build.
+    pub build: ContractBuild,
+}
+
+impl Output {
+    /// A shortcut constructor.
+    pub fn new(build: ContractBuild) -> Self {
+        Self { build }
+    }
+}