fix: about api access (#924)

below roles will have access to about api
- admin
- editor
- reader
- writer

ingestor does not need about api access as it cannot login or query.
This is required so clients like Console can decide on runtime about
which fields, pages to show to the logged in user.

Author: nikhilsinhaparseable

server/src/rbac/role.rs

@@ -207,6 +207,7 @@ pub mod model {
             actions: vec![
                 Action::Login,
                 Action::Metrics,
+                Action::GetAbout,
                 Action::Ingest,
                 Action::Query,
                 Action::CreateStream,
@@ -243,6 +244,7 @@ pub mod model {
         RoleBuilder {
             actions: vec![
                 Action::Login,
+                Action::GetAbout,
                 Action::Query,
                 Action::ListStream,
                 Action::GetSchema,
@@ -277,6 +279,7 @@ pub mod model {
         RoleBuilder {
             actions: vec![
                 Action::Login,
+                Action::GetAbout,
                 Action::Query,
                 Action::ListStream,
                 Action::GetSchema,