Support for 8MB APA Partitions, getStat Enhancements, apaRemove per APA specs

[AKuHAK]

This PR introduces the following changes:

• Reduces the minimum APA partition size from 128 MB to 8 MB.
• Fixes an issue where __empty partitions could exceed APA spec limits — they are now restricted to a maximum of 1 GB.
• Enhances getStat() to report the total partition size (main + all sub-partitions) using the private_1 and private_2 fields.

[AKuHAK]

I enabled in POSIX flag 8MB support as I didn't found any problems with it after massive testing. All this changes necessary for future pfs-shell improvements.
getStat change will also be useful for Athena project OSD-XMB

[uyjulian]

lgtm

[AKuHAK]

Doh, @uyjulian thanks for fast merge, but i kept one workaround there :D

ps2sdk/iop/hdd/libapa/src/apa.c

Lines 260 to 261 in 9c43697

	// TODO: switch to HDDDevices.partitionMaxSize
	u32 maxsize = 0x1FFFFF; // 1Gb

here wanna ask you if you know how to safely access HDDDevice.partitionMaxSize . Currently I limited empty partitions to be max 1Gb, but for disks larger than 80Gb APA specs allows larger single partitions (2Gb+), but current code will still limit empty to one Gb. Its definetly better than it was before, cause smaller partitions does not break APA specs, but still enforces fragmentation.