r/gitea: Handle encoded / characters in HTTP paths

Gitea package names (e.g. OCI images, etc.) can contain `/` charactres.
These are encoded as %2F in request paths.  Apache needs to forward
these sequences to the Gitea server without decoding them.
Unfortunately, the `AllowEncodedSlashes` setting, which controls this
behavior, is a per-virtualhost setting that is *not* inherited from the
main server configuration, and therefore must be explicitly set inside
the `VirtualHost` block.  This means Gitea needs its own virtual host
definition, and cannot rely on the default virtual host.

roles/gitea/templates/gitea.httpd.conf.j2

@@ -0,0 +1,25 @@
+# vim: set ft=apache :
+RewriteEngine on
+RewriteCond %{HTTPS} !on
+RewriteRule /.* https://%{SERVER_NAME}$0 [R=301,L]
+
+<VirtualHost _default_:443>
+    ServerName {{ gitea_http_domain }}
+
+    SSLCertificateFile {{ gitea_ssl_certificate }}
+    SSLCertificateKeyFile {{ gitea_ssl_certificate_key }}
+    SSLCertificateChainFile {{ gitea_ssl_certificate }}
+
+    RewriteEngine On
+    RewriteCond %{HTTPS} !on
+    RewriteRule /.* https://%{SERVER_NAME}$0
+
+    Header always set \
+        Strict-Transport-Security "max-age=63072000; includeSubDomains"
+
+    ProxyPreserveHost On
+    ProxyRequests Off
+    ProxyPass / http://localhost:3000/ nocanon
+    ProxyPassReverse / http://localhost:3000/
+    AllowEncodedSlashes NoDecode
+</VirtualHost>