Add THIRD-PARTY-NOTICES for vendored datasets

Signed-off-by: Émile Ré <emile@probo.com>

THIRD-PARTY-NOTICES

@@ -0,0 +1,45 @@
+Probo includes or uses data from the following third-party projects.
+
+================================================================================
+
+Open Cookie Database
+https://github.com/jkwakman/Open-Cookie-Database
+
+The `proboctl seed common-tracker-patterns` command clones this repository
+at runtime and imports cookie/tracker pattern data into the database.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+================================================================================
+
+country-ip-blocks
+https://github.com/ipverse/country-ip-blocks
+
+Country-level IPv4 and IPv6 prefix lists sourced from the five regional
+internet registries (RIR). Data files are vendored under
+pkg/geoloc/data/country-ip-blocks/ and used for IP geolocation.
+
+Released under CC0 1.0 Universal (public domain).
+https://creativecommons.org/publicdomain/zero/1.0/
+
+================================================================================
+
+disposable-email-domains
+https://github.com/disposable-email-domains/disposable-email-domains
+
+A community-maintained list of disposable email domains. Data files are
+vendored under pkg/validator/data/disposable-email-domains/ and used
+to reject sign-ups from throwaway email providers.
+
+Released under CC0 1.0 Universal (public domain).
+https://creativecommons.org/publicdomain/zero/1.0/