Reduce batch time for apps built in dev/debug mode

[DariaKunoichi]

Goal

While debugging developers don't want to wait for 30 seconds for spans to be sent and visible in dashboard.

Changeset

Reduce timeout needed to send spans from 30 sec to 5 sec in debug mode.
Added both info.plist option and configuration option for setting debug mode.

Testing

Added e2e test.

[github-actions]

BugsnagPerformance.framework binary size increased by 648 bytes from 855,360 to 856,008

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  +0.2%    +320  +0.2%    +320    Symbol Table
  +0.1%    +312  +0.1%    +312    String Table
  +0.2%    +288  +0.2%    +288    __TEXT,__text
  +0.5%    +168  +0.5%    +168    __DATA,__objc_const
  +0.4%     +98  +0.4%     +98    __TEXT,__objc_methname
  +0.5%     +96  +0.5%     +96    __TEXT,__objc_stubs
  +0.7%     +64  +0.7%     +64    __DATA_CONST,__cfstring
  +0.4%     +40  +0.4%     +40    __TEXT,__cstring
  +0.2%     +32  +0.2%     +32    __TEXT,__gcc_except_tab
  +0.5%     +24  +0.5%     +24    __DATA,__objc_selrefs
  +0.2%     +16  +0.2%     +16    __TEXT,__const
  +0.4%      +8  +0.4%      +8    Function Start Addresses
  +0.4%      +8  +0.4%      +8    Rebase Info
  +1.0%      +8  +1.0%      +8    __DATA,__objc_ivar
  -0.5%     -64  -0.5%     -64    [__DATA_CONST]
 -27.2%    -200 -34.2%    -200    [__DATA]
  -1.5%    -570  -1.5%    -570    [__TEXT]
  [ = ]       0  -5.0%    -648    [__LINKEDIT]
  +0.1%    +648  [ = ]       0    TOTAL

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