Bug 1842

Overview: Please add a confirmation before starting capture when there's already captured data, so that data is not silently lost

Steps to Reproduce:
1) Start Pulseview
2) Click Run. After 5 seconds the capture ends as the 1M samples are captured
3) Click Run again. Pulseview starts capturing again, losing the previous capture

Actual Results:
At step 3, the previous capture is lost.

Expected Results:
Ideally, I would like pulseview to offer to either;
-Append the new capture to the already captured data
-Save the old data, and start a new capture
-Discard the old data (with a second confirmation to be extra sure)

Build Date & Hardware: I build it myself on 04/15/2023 on a 64 bit AMD machine, using the Demo Device.

Versions, libraries and features:
PulseView
0.5.0-git-62c0968
Qt
5.15.9
glibmm
2.66.6
Boost
1_81
exprtk
20200101
libsigrok
0.6.0-git/4:0:0 (rt: 0.6.0-git-5bce22ac/4:0:0)
- glib
2.76.1 (rt: 2.76.1/7601:1)
- zlib
1.2.13
- libzip
1.9.2
- minilzo
2.10
- libserialport
0.1.1/1:0:1 (rt: 0.1.1/1:0:1)
- libusb-1.0
1.0.26.11724 API 0x01000109
- hidapi
0.13.1
- bluez
5.66
- libftdi
1.5
- Host
x86_64-pc-linux-gnu, little-endian
- SCPI backends
TCP, RPC, serial, USBTMC
libsigrokdecode
0.6.0-git-d7da8b9/4:0:0 (rt: 0.6.0-git-d7da8b9/4:0:0)
- glib
2.76.1 (rt: 2.76.1/7601:1)
- Python
3.10.10 / 0x30a0af0 (API 1013, ABI 3)
- Host
x86_64-pc-linux-gnu, little-endian
$ uname -a 
Linux cedric 6.2.11-arch1-1 #1 SMP PREEMPT_DYNAMIC Thu, 13 Apr 2023 16:59:24 +0000 x86_64 GNU/Linux

Additional Builds and Platforms:
Not tested

Additional Information: