[chore/bugfix] Domain block tidying up, Implement first pass of 207 Multi-Status (#1886)

* [chore/refactor] update domain block processing

* expose domain block import errors a lil better

* move/remove unused query keys

internal/api/client/admin/domainblocksget.go

@@ -20,7 +20,6 @@ package admin
 import (
 	"fmt"
 	"net/http"
-	"strconv"
 
 	"github.com/gin-gonic/gin"
 	apiutil "github.com/superseriousbusiness/gotosocial/internal/api/util"
@@ -92,16 +91,10 @@ func (m *Module) DomainBlocksGETHandler(c *gin.Context) {
 		return
 	}
 
-	export := false
-	exportString := c.Query(ExportQueryKey)
-	if exportString != "" {
-		i, err := strconv.ParseBool(exportString)
-		if err != nil {
-			err := fmt.Errorf("error parsing %s: %s", ExportQueryKey, err)
-			apiutil.ErrorHandler(c, gtserror.NewErrorBadRequest(err, err.Error()), m.processor.InstanceGetV1)
-			return
-		}
-		export = i
+	export, errWithCode := apiutil.ParseDomainBlockExport(c.Query(apiutil.DomainBlockExportKey), false)
+	if errWithCode != nil {
+		apiutil.ErrorHandler(c, errWithCode, m.processor.InstanceGetV1)
+		return
 	}
 
 	domainBlocks, errWithCode := m.processor.Admin().DomainBlocksGet(c.Request.Context(), authed.Account, export)