Revisions to System::Layer

[kpschoedel]

Problem

System::Layer has redundancy in event configuration,
and a confusingly-named grab-bag namespace System::Platform::Layer

This is a standalone fragment of work toward event/threading
refactoring, issue #7725.

Change overview

• Merge CHIP_SYSTEM_CONFIG_LWIP_EVENT_OBJECT_TYPE with
  CHIP_SYSTEM_CONFIG_EVENT_OBJECT_TYPE, and
  CHIP_SYSTEM_CONFIG_LWIP_EVENT_TYPE with
  CHIP_SYSTEM_CONFIG_EVENT_TYPE, since they serve the same purpose
  in LwIP and non-LwIP implementations respectively.
• Remove some dead configuration code.
• Move event functions from the System::Platform::Layer namespace
  (not the same kind of ‘layer’ as System::Layer) to a specific
  System::Platform::EventSupport namespace.
• Move (Will|Did)(Init|Shutdown) functions from the
  System::Platform::Layer namespace up to System::Platform.

Testing

No functional changes, only renaming and pruning.

[andy31415]

nitpick: do we need "Support" in the name here? I generally claim that support/helper/core/util and similar naming do not add significant readability. Could we get around with just "Eventing" or "Events" ?

[kpschoedel]

Sure, will rename in the next PR.

[github-actions]

Size increase report for "esp32-example-build" from cbf106e

File	Section	File	VM
chip-all-clusters-app.elf	.flash.text	-16	-16
chip-lock-app.elf	.flash.text	64	64

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-pigweed-app.elf and ./pull_artifact/chip-pigweed-app.elf:

sections,vmsize,filesize
.debug_loc,0,-3
.debug_abbrev,0,-14
.debug_info,0,-39

Comparing ./master_artifact/chip-persistent-storage.elf and ./pull_artifact/chip-persistent-storage.elf:

sections,vmsize,filesize
.debug_loc,0,-6
.debug_line,0,-258
.debug_abbrev,0,-1375
.debug_str,0,-4866
.debug_info,0,-10739

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

sections,vmsize,filesize
.debug_str,0,20
.strtab,0,16
.debug_loc,0,-19
.debug_line,0,-1584
.debug_abbrev,0,-7764
.debug_info,0,-67273

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

sections,vmsize,filesize
.xt.prop._ZN4chip6System5Mutex6UnlockEv,0,108
.xt.lit._ZN4chip11DeviceLayer8Internal35GenericPlatformManagerImpl_FreeRTOSINS0_19PlatformManagerImplEE14_LockChipStackEv,0,48
.xt.lit._ZN4chip11DeviceLayer8Internal35GenericPlatformManagerImpl_FreeRTOSINS0_19PlatformManagerImplEE15_StartChipTimerEj,0,48
.xt.lit._ZN4chip11DeviceLayer8Internal35GenericPlatformManagerImpl_FreeRTOSINS0_19PlatformManagerImplEE16_UnlockChipStackEv,0,48
.debug_str,0,23
.strtab,0,16
[Unmapped],0,16
.xt.prop._ZN4chip11DeviceLayer8Internal35GenericPlatformManagerImpl_FreeRTOSINS0_19PlatformManagerImplEE14_LockChipStackEv,0,12
.xt.prop._ZN4chip11DeviceLayer8Internal35GenericPlatformManagerImpl_FreeRTOSINS0_19PlatformManagerImplEE15_StartChipTimerEj,0,12
.xt.prop._ZN4chip11DeviceLayer8Internal35GenericPlatformManagerImpl_FreeRTOSINS0_19PlatformManagerImplEE16_UnlockChipStackEv,0,12
.flash.text,-16,-16
.debug_loc,0,-29
.xt.prop._ZN4chip11DeviceLayer8Internal26GenericPlatformManagerImplINS0_19PlatformManagerImplEE14_InitChipStackEv,0,-40
.xt.lit._ZN4chip11DeviceLayer8Internal35GenericPlatformManagerImpl_FreeRTOSINS0_19PlatformManagerImplEE10_PostEventEPKNS0_15ChipDeviceEventE,0,-80
.xt.lit._ZN4chip6System5Mutex6UnlockEv,0,-128
.debug_line,0,-4575
.debug_abbrev,0,-20509
.debug_info,0,-193982

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

sections,vmsize,filesize
.flash.text,64,64
.debug_str,0,22
.strtab,0,16
.debug_loc,0,10
[Unmapped],0,-64
.debug_line,0,-86
.debug_abbrev,0,-881
.debug_info,0,-8977

Comparing ./master_artifact/chip-temperature-measurement-app.elf and ./pull_artifact/chip-temperature-measurement-app.elf:

sections,vmsize,filesize
.debug_str,0,20
.strtab,0,16
.debug_loc,0,-37
.debug_line,0,-4124
.debug_abbrev,0,-18698
.debug_info,0,-174441