workspace: Clip to allocation when not in window picker state

We want to avoid windows that are overlapping the monitor edges from
overflowing the small workspace strip when showing the app grid. To do
that, enable clip_to_allocation on the Workspace actor when our
stateAdjustment value is 0. The reason we can't use
"stateAdjustement !== 1" here is that the app icons we show above the
previews overflow the allocation, and those would get clipped while
they're animating in/out.

Fixes #3716
11 jobs for !1690 with fix-overflowing in 2 minutes and 35 seconds (queued for 2 seconds)
detached
Status Job ID Name Coverage
  Pre Review
passed #1161138
check_commit_log

00:00:22

passed #1161139
check-merge-request

00:00:16

 
  Prep
passed #1161140
build-fedora-container

00:00:28

 
  Review
passed #1161142
eslint

00:01:21

passed #1161143
eslint_mr

00:01:05

passed #1161141
js_check

00:00:36

passed #1161145
no_template_check

00:00:12

passed #1161144
potfile_check

00:00:28

 
  Build
passed #1161146
build

00:01:41

passed #1161147
flatpak
flatpak

00:01:24

 
  Test
passed #1161148
test

00:00:30