remove unused link member from KeyboardGroup

unnecessary since grouping Keyboard wl_list to use wlr_keyboard_group in 023efce

ΔSLOC: -1

disable scene node unless it is unmanaged

send a configure to unmanaged clients when mapping

configure xdg_toplevels after configuring it's decoration

remove a space before parenthesis in function calls

destroy popups when we can't get it's parent or they don't have monitor

remove a redundant check

resize() now does the same check

avoid using a else block

introduce client_set_scale()

remove unnecessary LayerShell.geom

We only used geom.x and geom.y. We can access those variables directly from the
scene node.

update comment about first fields of Client and LayerSurface order

fix style in configurex11()

fix crash when a client is created while all outputs are disabled

use wlr_scene_set_gamma_control_manager_v1() (wlroots!4192)

References: https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/4192

guarantee client_get_{title,appid} never return NULL

ΔSLOC: -6

fix potential crash in configurex11()

We can't call resize() on unmanaged clients because they don't have borders and
resize() requires them.

Fixes: 94f4ead7dad89433e6087dc19950738c64bbed05

account border width in configurex11()

Fixes: 13925eb1da8af2c1d23ee9d01efd03c3626081b2

actually move unmanaged clients in configurex11()

only calling wlr_xwayland_surface_configure() may be not enough because we also
need to move the scene node in order to make effective the configure

improve checking in configurex11()

this avoids a client resizing itself when the user is interactively resizing
the client

drop a useless check in configurex11()