Fixed issue board label filtering not removing labels

## What does this MR do?

When trying to remove a label filter it would actually add it instead making it impossible to remove the label filter without modifying the URL. This fixes that by correctly removing the label from the filter.

## What are the relevant issue numbers?

Closes #21417

See merge request !6208

Improve project_with_board factory to create the default lists

## What does this MR do?

Create the default lists after creating a project with the `project_with_board` factory. This makes the setup phase on tests be more simpler.

## Why was this MR needed?

These two lists are present in every issue board, so we don't have to create them manually in every test.

See merge request !6480

Fixed list issues not loading with spaces in filtered values

## What does this MR do?

Vue resource is very kindly encoding our URL params when sending. However - we didn't actually want the `+` to be encoded because Rails reads that as a space, but doesn't read the encoded value as a space :confused: 

This converts the `+` into spaces :thumbsup: 

## What are the relevant issue numbers?

Closes #21920

See merge request !6258

Originally created to address #21197, but !6224 solved the intermittent spec
failures.

Added wait for vue helper