Build summary: Report information on all enabled memory devices how DTS partitions them

[de-nordic]

Is your feature request related to a problem? Please describe.
The flash, or possibly other memory devices, area partitioned via DTS, and such partitioning may be applied via multiple overlays, which allows to create overlaying partitions or accidentally left some space unassigned.
The feature would not affect build in any other way than just displaying information, without categorizing anything as problem.

Describe the solution you'd like
I would like to propose to improve gen_defines.py or add additional script that would parse the final DTS file and
print table of enabled ("status" == "okay") memory devices, for example flash, with partitions that are created on them (and enabled), information on space that has not been allocated, and overlapping allocations.
The list may be similar to the fdisk output, or similar tool for Linux/Unix; or be something similar to:

Device flash0 at flash-controller@4001e000 allocation:
        DTS Label       Offset          Size            Overlaps
        mcuboot         0x0000          0x0c000
        image-1         0x0c000         0x02000         image-1, single
        image-2         0x0d000         0x02000         single, image-2
        single          0x0c000         0x04000         image-1, image-2
        <unused>        0x10000         0x10000
        storage         0x20000         0x02000
Device (...):
        ...

Describe alternatives you've considered
There is not such solution within Zephyr yet, the closest possible solution is proposed by @JordanYates #33656, but it is more related to fixing problems with compilation and linking. Note that the PR is actually presenting table of "regions" at the build completion, but is is slightly different as it presents how much of flash has been designated for "region" and how much will be occupied according to linker output.

Additional context
Here are pull requests that are trying to fix problem with compiler/linker being unaware of boundaries the app should be fit to; they are not directly impacted or impacting the feature but they are working with similar issue, but with different impact on build:
@carlocaione's #35460
@JordanYates' #33656

[zephyrbot]

Hi @tejlmand,

This issue, marked as an Enhancement, was opened a while ago and did not get any traction. It was just assigned to you based on the labels. If you don't consider yourself the right person to address this issue, please re-assing it to the right person.

Please take a moment to review if the issue is still relevant to the project. If it is, please provide feedback and direction on how to move forward. If it is not, has already been addressed, is a duplicate, or is no longer relevant, please close it with a short comment explaining the reason.

@de-nordic you are also encouraged to help moving this issue forward by providing additional information and confirming this request/issue is still relevant to you.

Thanks!