feat: golang switch

Switches the project from Python to Golang. This commit includes the following changes:
- validation mode
- redis caching
- resource validation mode
- notary: support for all TUF keys
- unified "*" trustRoot option
- update of cosign to 2.2.3
- custom labels (adapted from @jimonthebarn)

Author: phbelitz

.dockerignore

@@ -1,13 +1,15 @@
-# ignore Markdown files
+# ignore docs
 *.md
+docs/
 # ignore tests
-connaisseur/tests/
-# ignore img
-img/
-# ignore coverage files
-connaisseur/coverage.xml
-connaisseur/coverage.txt
-# ignore pycache
-connaisseur/__pycache__/
-# ignore venv folder
-venv/
+tests/
+test/
+# ignore tools
+tools/
+# ignore charts
+charts/
+helm/
+# ignore misc
+LICENSE
+Makefile
+mkdocs.yml