Enable formatting for blockdata

Add `rustfmt::skip` attribute in a couple of places and then remove the
exclude for the `blockdata` module. Do not run the formatter, that will
be done as a separate patch to aid review.

bitcoin/src/blockdata/opcodes.rs

@@ -351,6 +351,7 @@ impl All {
             (OP_VERIF, _) | (OP_VERNOTIF, _) | (OP_INVALIDOPCODE, _) => Class::IllegalOp,
 
             // 15 opcodes illegal in Legacy context
+            #[rustfmt::skip]
             (OP_CAT, ctx) | (OP_SUBSTR, ctx)
             | (OP_LEFT, ctx) | (OP_RIGHT, ctx)
             | (OP_INVERT, ctx)

bitcoin/src/blockdata/script/tests.rs

@@ -11,6 +11,7 @@ use crate::psbt::serialize::Serialize;
 use hex_lit::hex;
 
 #[test]
+#[rustfmt::skip]
 fn script() {
     let mut comp = vec![];
     let mut script = Builder::new();

rustfmt.toml

@@ -1,6 +1,5 @@
 # Eventually this shoud be: ignore = []
 ignore = [
-       "bitcoin/src/blockdata",
        "bitcoin/src/util",
        "hashes",
 ]