Add id parsing benchmarks

Initial results:

    running 4 tests
    test hash_wikidata   ... bench:          14 ns/iter (+/- 0)
    test hash_wikipedia  ... bench:          34 ns/iter (+/- 1)
    test parse_wikidata  ... bench:          18 ns/iter (+/- 0)
    test parse_wikipedia ... bench:      60,682 ns/iter (+/- 83,376)

Based on these results and a flamegraph of loading the file, url parsing
is the most expensive part.

Signed-off-by: Evan Lloyd New-Schmidt <evan@new-schmidt.com>

benches/id_parsing.rs

@@ -0,0 +1,43 @@
+#![feature(test)]
+use std::{collections::HashSet, str::FromStr};
+
+extern crate om_wikiparser;
+extern crate test;
+
+#[bench]
+fn parse_wikipedia(b: &mut test::Bencher) {
+    b.iter(|| {
+        let title = om_wikiparser::wm::WikipediaTitleNorm::from_url(
+            "https://en.wikipedia.org/wiki/Article_Title",
+        )
+        .unwrap();
+    });
+}
+
+#[bench]
+fn hash_wikipedia(b: &mut test::Bencher) {
+    let title = om_wikiparser::wm::WikipediaTitleNorm::from_url(
+        "https://en.wikipedia.org/wiki/Article_Title",
+    )
+    .unwrap();
+    let mut set = HashSet::new();
+    b.iter(|| {
+        set.insert(&title);
+    });
+}
+
+#[bench]
+fn parse_wikidata(b: &mut test::Bencher) {
+    b.iter(|| {
+        let qid = om_wikiparser::wm::WikidataQid::from_str("Q123456789").unwrap();
+    });
+}
+
+#[bench]
+fn hash_wikidata(b: &mut test::Bencher) {
+    let qid = om_wikiparser::wm::WikidataQid::from_str("Q123456789").unwrap();
+    let mut set = HashSet::new();
+    b.iter(|| {
+        set.insert(&qid);
+    });
+}