Adds P7012 extension with RDF and HTML

- Adds P7012 extension under `2.1-dev/standards/p7012`
- Contains RDF and HTML outputs for P7012
- The status of the extension is DRAFT
- See #203

Co-authored-by: Iain Henderson <[email protected]>
Co-authored-by: Beatriz Esteves <[email protected]>

Squashed commit of the following:

commit 1d3a678
Author: Harshvardhan Pandit <[email protected]>
Date:   Sun Jan 12 21:30:33 2025 +0000

    WIP: Adds P7012 HTML

commit 47d6acb
Author: Harshvardhan Pandit <[email protected]>
Date:   Sun Jan 12 19:09:50 2025 +0000

    WIP: Adds P7012 RDF

commit 25b9726
Author: Harshvardhan Pandit <[email protected]>
Date:   Sun Jan 12 18:47:38 2025 +0000

    WIP: Adds P7012 CSV sources

2.1-dev/diagrams/p7012-process-overview.plantuml

@@ -0,0 +1,35 @@
+@startuml
+!theme plain
+actor Person as P
+actor PersonAgent as PA
+actor ProviderAgent as PRA
+actor ServiceProvider as SP
+
+P --> PA : Sets preferences (PP)
+PRA --> PA : Query for P7012 contract initiation
+PA --> PRA : P7012 supported
+
+alt Contract Supported
+    PRA --> PA : Request PrivacyTerm (
+    PA --> PRA : Provide PrivacyTerm reference in Registry
+
+    PRA --> PRA : Determines acceptability of term
+
+    alt Term Acceptable
+        PRA --> PA : Initiate and execute contract
+        PA --> PA : Record contract process
+    else Term Unacceptable - Offer Negotiation
+        PRA --> PA : Offer alternative PrivacyTerm reference in Registry
+
+        alt Alternative Term Acceptable
+            PA --> PRA : PrivacyTerm acceptable
+            PRA --> PA : Initiate and execute contract
+            PA --> PA : Record contract process
+        else Term Unacceptable
+            note over PRA, PA : Contract process terminates
+        end
+    end
+else Contract Not Supported
+    note over PRA, PA : No contract initiation
+end
+@enduml