Rename EcPublicKeyX509Der to PublicKeyX509Der #48

Job	Run time
clippy (aws-lc-rs, --features bindgen,unstable)	1m 13s
mirai-analysis	2m 41s
clippy (aws-lc-rs, --features bindgen,unstable,fips)	1m 22s
dependency-review	21s
apidiff (aws-lc-sys, branch)	2m 4s
apidiff (aws-lc-sys, published)	2m 19s
rustfmt	36s
apidiff (aws-lc-fips-sys, branch)	2m 54s
udeps	7m 39s
apidiff (aws-lc-fips-sys, published)	2m 37s
apidiff (aws-lc-rs, branch)	3m 5s
apidiff (aws-lc-rs, published)	2m 18s
copyright	5s
Resolve the dependencies to the minimum SemVer version	42s
Minimum Supported Rust Version	5m 11s
semver-checks	1m 6s
	36m 13s

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