[server] Enhance server storage logs

[Damian-Nordic]

Problem

Currently, applications print lots of "Retrieved value from server storage" messages on startup, even if the value was
actually not found in the storage.

Change overview

Make sure the logs are printed only when a value is really loaded, stored or deleted and add information about the key.

Testing

Tested manually with Linux and nRF Connect applications.

[github-actions]

Size increase report for "gn_qpg-example-build" from e9ec676

File	Section	File	VM
chip-qpg6100-lighting-example.out	.text	-4	-4

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-qpg6100-lighting-example.out.map and ./pull_artifact/chip-qpg6100-lighting-example.out.map:

BLOAT EXECUTION FAILED WITH CODE 1:
bloaty: unknown file type for file './pull_artifact/chip-qpg6100-lighting-example.out.map'

Comparing ./master_artifact/chip-qpg6100-lighting-example.out and ./pull_artifact/chip-qpg6100-lighting-example.out:

sections,vmsize,filesize
.debug_info,0,537
.debug_loc,0,303
.debug_line,0,173
.debug_ranges,0,152
[Unmapped],0,4
.debug_str,0,-1
.text,-4,-4
.debug_frame,0,-12

[github-actions]

Size increase report for "nrfconnect-example-build" from e9ec676

File	Section	File	VM
chip-lock.elf	rodata	-8	-4

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-shell.elf and ./pull_artifact/chip-shell.elf:

sections,vmsize,filesize

Comparing ./master_artifact/chip-lock.elf and ./pull_artifact/chip-lock.elf:

sections,vmsize,filesize
.debug_info,0,537
.debug_loc,0,240
.debug_line,0,171
.debug_ranges,0,152
rodata,-4,-8
.debug_frame,0,-12

[github-actions]

Size increase report for "esp32-example-build" from e9ec676

File	Section	File	VM
chip-all-clusters-app.elf	.flash.text	-8	-8

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-all-clusters-app.elf and ./pull_artifact/chip-all-clusters-app.elf:

sections,vmsize,filesize
.debug_info,0,96
.debug_ranges,0,96
.debug_abbrev,0,10
[Unmapped],0,8
.riscv.attributes,0,1
.flash.text,-8,-8
.debug_frame,0,-20
.debug_line,0,-121
.debug_loc,0,-146