Clear all HTTP request logs (#49)

* Create mutation to clear request logs

* Add UI for clearing all HTTP request logs

* Use consistent naming

* Explicitly delete only from http_requests

* Check if datebase is open

* Add confirmation dialog

pkg/api/schema.graphql

@@ -58,6 +58,10 @@ type DeleteProjectResult {
   success: Boolean!
 }
 
+type ClearHTTPRequestLogResult {
+  success: Boolean!
+}
+
 input HttpRequestLogFilterInput {
   onlyInScope: Boolean
 }
@@ -79,6 +83,7 @@ type Mutation {
   openProject(name: String!): Project
   closeProject: CloseProjectResult!
   deleteProject(name: String!): DeleteProjectResult!
+  clearHTTPRequestLog: ClearHTTPRequestLogResult!
   setScope(scope: [ScopeRuleInput!]!): [ScopeRule!]!
   setHttpRequestLogFilter(
     filter: HttpRequestLogFilterInput