[chore] The Big Middleware and API Refactor (tm) (#1250)

* interim commit: start refactoring middlewares into package under router

* another interim commit, this is becoming a big job

* another fucking massive interim commit

* refactor bookmarks to new style

* ambassador, wiz zeze commits you are spoiling uz

* she compiles, we're getting there

* we're just normal men; we're just innocent men

* apiutil

* whoopsie

* i'm glad noone reads commit msgs haha :blob_sweat:

* use that weirdo go-bytesize library for maxMultipartMemory

* fix media module paths

internal/web/assets.go

@@ -22,11 +22,9 @@ import (
 	"fmt"
 	"net/http"
 	"path"
-	"path/filepath"
 	"strings"
 
 	"github.com/gin-gonic/gin"
-	"github.com/superseriousbusiness/gotosocial/internal/config"
 	"github.com/superseriousbusiness/gotosocial/internal/log"
 )
 
@@ -53,22 +51,6 @@ func (fs fileSystem) Open(path string) (http.File, error) {
 	return f, nil
 }
 
-func (m *Module) mountAssetsFilesystem(group *gin.RouterGroup) {
-	webAssetsAbsFilePath, err := filepath.Abs(config.GetWebAssetBaseDir())
-	if err != nil {
-		log.Panicf("mountAssetsFilesystem: error getting absolute path of assets dir: %s", err)
-	}
-
-	fs := fileSystem{http.Dir(webAssetsAbsFilePath)}
-
-	// use the cache middleware on all handlers in this group
-	group.Use(m.assetsCacheControlMiddleware(fs))
-
-	// serve static file system in the root of this group,
-	// will end up being something like "/assets/"
-	group.StaticFS("/", fs)
-}
-
 // getAssetFileInfo tries to fetch the ETag for the given filePath from the module's
 // assetsETagCache. If it can't be found there, it uses the provided http.FileSystem
 // to generate a new ETag to go in the cache, which it then returns.
@@ -115,6 +97,9 @@ func (m *Module) getAssetETag(filePath string, fs http.FileSystem) (string, erro
 //
 // See: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-None-Match
 // and: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control
+//
+// todo: move this middleware out of the 'web' package and into the 'middleware'
+// package along with the other middlewares
 func (m *Module) assetsCacheControlMiddleware(fs http.FileSystem) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		// set this Cache-Control header to instruct clients to validate the response with us