samples: Fix configuration scheme

[ktaborowski]

wrong configuration schema with pm_static files. It's not recommended to use PM_STATIC_YML_FILE in the sample CMakeLists because it do not allow users to overwrite it.
See nrfconnect/sdk-nrf#14281

In this commit:

• Removed redundant prj_no_dfu.conf configuration.
• moved all pm_static files to samples' main directories and renamed them to be consistent with the NCS build system and partition manager requirements.
• Updated documentation regarding the changes.

CI parameters

(branch, hash, pull/XXX/head)
NRF_revision=main

manifest-pr-skip

Description

JIRA ticket:

Detail description of the change

Self review

• There is no commented code.
• There is no TODO/FIXME comments without associated issue ticket.
• Commits are properly organized
• Verification
  • Unit tests were updated to include the change.
  • Change has been tested.

[github-actions]

Sample		diff	used	total
nrf54l15pdk_nrf54l15_cpuapp:sample.sidewalk.dut	RAM	0 B	121.36 KB	256 KB
	ROM	40 B	414.93 KB	730 KB
nrf54l15pdk_nrf54l15_cpuapp:sample.sidewalk.hello	RAM	0 B	87.74 KB	256 KB
	ROM	-88 B	350.85 KB	730 KB
nrf54l15pdk_nrf54l15_cpuapp:sample.sidewalk.hello.ble_only	RAM	0 B	87.74 KB	256 KB
	ROM	-88 B	350.6 KB	730 KB
nrf54l15pdk_nrf54l15_cpuapp:sample.sidewalk.hello.no_dfu	RAM	-74.47 KB	0 B	256 KB
	ROM	-332.18 KB	0 B	1.48 MB
thingy53_nrf5340_cpuapp:sample.sidewalk.demo.ble_only	RAM	0 B	102.42 KB	440 KB
	ROM	8 B	390.86 KB	975.5 KB
nrf52840dk_nrf52840:sample.sidewalk.demo	RAM	0 B	119.83 KB	256 KB
	ROM	-8 B	495.27 KB	983.5 KB
nrf52840dk_nrf52840:sample.sidewalk.demo.ble_only	RAM	128 B	104.33 KB	256 KB
	ROM	-4 B	412.82 KB	983.5 KB
nrf52840dk_nrf52840:sample.sidewalk.dut	RAM	0 B	143.21 KB	256 KB
	ROM	40 B	554.23 KB	983.5 KB
nrf52840dk_nrf52840:sample.sidewalk.hello	RAM	0 B	109.58 KB	256 KB
	ROM	-88 B	494.89 KB	983.5 KB
nrf52840dk_nrf52840:sample.sidewalk.hello.ble_only	RAM	0 B	94.08 KB	256 KB
	ROM	-72 B	412.22 KB	983.5 KB
nrf52840dk_nrf52840:sample.sidewalk.hello.no_dfu	RAM	-96.29 KB	0 B	256 KB
	ROM	-477.17 KB	0 B	983.5 KB
nrf5340dk_nrf5340_cpuapp:sample.sidewalk.demo	RAM	0 B	108.09 KB	440 KB
	ROM	-4 B	433.1 KB	975.5 KB
nrf5340dk_nrf5340_cpuapp:sample.sidewalk.demo.ble_only	RAM	0 B	92.89 KB	440 KB
	ROM	-8 B	354.45 KB	975.5 KB
nrf5340dk_nrf5340_cpuapp:sample.sidewalk.dut	RAM	0 B	131.55 KB	440 KB
	ROM	40 B	492.09 KB	975.5 KB
nrf5340dk_nrf5340_cpuapp:sample.sidewalk.hello	RAM	0 B	98.18 KB	440 KB
	ROM	-72 B	432.81 KB	975.5 KB
nrf5340dk_nrf5340_cpuapp:sample.sidewalk.hello.ble_only	RAM	0 B	82.97 KB	440 KB
	ROM	-84 B	354.11 KB	975.5 KB
nrf5340dk_nrf5340_cpuapp:sample.sidewalk.hello.no_dfu	RAM	-84.95 KB	0 B	440 KB
	ROM	-414.93 KB	0 B	975.5 KB
nrf54l15pdk_nrf54l15_cpuapp:sample.sidewalk.demo	RAM	0 B	97.69 KB	256 KB
	ROM	-8 B	351.45 KB	730 KB
nrf54l15pdk_nrf54l15_cpuapp:sample.sidewalk.demo.ble_only	RAM	0 B	97.69 KB	256 KB
	ROM	-8 B	351.2 KB	730 KB

[ktaborowski]

included in #541