Code Cleanup: unused includes, useless checks, unused variables, etc... (#3696)

* Remove unnecessary checks
* Sublime: never insert missing headers
* Cleanup furi defines use
* Cleanup startup. Cleanup linker scripts. Explicitly define all interrupts hadlers, including uninmplemented one.
* Startup routine in C
* Drop assembler startup
* Move linker defines to stm32wb55_linker.h, cleanup naming, unify usage. Mpu: protect last 32b of main stack. Document various obscure things.
* Move furi_hal_switch documentation to appropriate place, use 0x0 for updater jump.
* UnitTests: move all temporary test files into tmp folder

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Co-authored-by: SG <who.just.the.doctor@gmail.com>

targets/f7/src/update.c

@@ -109,7 +109,7 @@ static bool flipper_update_load_stage(const FuriString* work_dir, UpdateManifest
 
         memmove((void*)(SRAM1_BASE), img, stat.fsize);
         LL_SYSCFG_SetRemapMemory(LL_SYSCFG_REMAP_SRAM);
-        furi_hal_switch((void*)SRAM1_BASE);
+        furi_hal_switch(0x0);
         return true;
 
     } while(false);