[feature] Conversations API (#3013)

* Implement conversations API

* Sort and page conversations by last status ID

* Appease linter

* Fix deleting conversations and statuses

* Refactor to make migrations automatic

* Lint

* Update tests post-merge

* Fixes from live-fire testing

* Linter caught a format problem

* Refactor tests, fix cache

* Negative test for non-DMs

* Run conversations advanced migration on testrig startup as well as regular server startup

* Document (lack of) side effects of API method for deleting a conversation

* Make not-found check less nested for readability

* Rename PutConversation to UpsertConversation

* Use util.Ptr instead of IIFE

* Reduce cache used by conversations

* Remove unnecessary TableExpr/ColumnExpr

* Use struct tags for both unique constraints on Conversation

* Make it clear how paging with GetDirectStatusIDsBatch should be used

* Let conversation paging skip conversations it can't render

* Use Bun NewDropTable

* Convert delete raw query to Bun

* Convert update raw query to Bun

* Convert latestConversationStatusesTempTable raw query partially to Bun

* Convert conversationStatusesTempTable raw query partially to Bun

* Rename field used to store result of MaxDirectStatusID

* Move advanced migrations to their own tiny processor

* Catch up util function name with main

* Remove json.… wrappers

* Remove redundant check

* Combine error checks

* Replace map with slice of structs

* Address processor/type converter comments

- Add context info for errors
- Extract some common processor code into shared methods
- Move conversation eligibility check ahead of populating conversation

* Add error context when dropping temp tables

internal/processing/workers/workers.go

@@ -22,6 +22,7 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/federation"
 	"github.com/superseriousbusiness/gotosocial/internal/filter/visibility"
 	"github.com/superseriousbusiness/gotosocial/internal/processing/account"
+	"github.com/superseriousbusiness/gotosocial/internal/processing/conversations"
 	"github.com/superseriousbusiness/gotosocial/internal/processing/media"
 	"github.com/superseriousbusiness/gotosocial/internal/processing/stream"
 	"github.com/superseriousbusiness/gotosocial/internal/state"
@@ -44,6 +45,7 @@ func New(
 	account *account.Processor,
 	media *media.Processor,
 	stream *stream.Processor,
+	conversations *conversations.Processor,
 ) Processor {
 	// Init federate logic
 	// wrapper struct.
@@ -56,11 +58,12 @@ func New(
 	// Init surface logic
 	// wrapper struct.
 	surface := &Surface{
-		State:       state,
-		Converter:   converter,
-		Stream:      stream,
-		Filter:      filter,
-		EmailSender: emailSender,
+		State:         state,
+		Converter:     converter,
+		Stream:        stream,
+		Filter:        filter,
+		EmailSender:   emailSender,
+		Conversations: conversations,
 	}
 
 	// Init shared util funcs.