cmake-gui: Restore search bar for cache view and environment dialog

This was broken by commit f1de6f66 (cmake-gui: Support building
against Qt6, 2020-12-17, v3.20.0-rc1~205^2~7).

Fixes: #21850
47 jobs for !5845 with fix-search in 36 minutes and 39 seconds (queued for 2 seconds)
latest detached
Status Job ID Name Coverage
  Build
passed #5556800
build cmake docker linux manual
build:centos6-x86_64

00:03:55

passed #5556747
linux docker build cmake
build:debian10-iwyu

00:02:37

passed #5556751
linux-3.17 linux docker build cmake manual
build:fedora33-ninja

00:04:38

passed #5556749
linux-3.17 linux docker build cmake
build:fedora33-sphinx

00:05:02

passed #5556748
linux-3.17 linux docker build cmake
build:fedora33-tidy

00:03:52

passed #5556753
nonconcurrent xcode-12.3 shell macos cmake manual
build:macos-makefiles

00:03:27

manual #5556752
nonconcurrent xcode-12.3 shell macos cmake manual
build:macos-ninja
passed #5556754
nonconcurrent msvc-19.28 vs2019 shell windows cmake manual
build:windows-vs2019-x64-ninja

00:02:41

failed #5556750
linux docker build cmake manual
build:centos6-x86_64

00:04:19

 
  Test
passed #5556755
x11 linux-3.17 linux docker cmake
test:fedora33-ninja

00:04:03

passed #5556757
nonconcurrent xcode-12.3 shell macos cmake
test:macos-makefiles

00:10:26

created #5556756
nonconcurrent xcode-12.3 shell macos cmake
test:macos-ninja
passed #5556799
msvc-19.28 nonconcurrent vs2019 shell cmake windows
test:windows-vs2019-x64-ninja

00:25:16

failed #5556758
nonconcurrent msvc-19.28 vs2019 shell windows cmake
test:windows-vs2019-x64-ninja

00:05:36

 
  Test Ext
passed #5556761
linux docker cuda-rt cmake
test:cuda10.2-nvidia

00:01:52

passed #5556759
linux-3.17 linux docker build cmake
test:debian10-ninja

00:02:15

passed #5556760
linux-3.17 linux docker build cmake
test:fedora33-makefiles

00:02:45

passed #5556762
linux-3.17 linux docker build cmake
test:fedora33-ninja-multi

00:03:04

canceled #5556763
concurrent xcode-12.3 shell macos cmake
test:macos-xcode

canceled #5556764
concurrent msvc-19.28 vs2019 shell windows cmake
test:windows-vs2019-x64

 
  External
passed cdash

passed ghostflow-check-master

passed ghostflow-check-release

passed ghostflow-stager

passed cdash

passed cdash

passed cdash

passed cdash

passed cdash

passed cdash

passed cdash

passed cdash

passed cdash

passed cdash

passed cdash

passed cdash

passed ghostflow-check-master

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager