In save selection, warn the user the selection is too large before attempting to read a too large selection and go OOM

[xusheng6]

User report:

Hi Guys, I'm getting a regular (but not everytime) crash when selecting a large binary blob and saving the selection to disk.

Process:
Right click address -> Selection -> Extend to end of binaryRight click -> selection -> Save To..
It crashes as soon as you click Save To, more often than not.

BN Ver: 6.0.10501-dev on Windows 11

Appears to only be when debugging

I believe this is bc during debugging, that "extend to the end of the binary" would send it to 0xffffffffffffffff, which would leave to am OOO

though I am curious what happened when it did not crash

[sentry]

Sentry Issue: BINARYNINJA-MC

[xusheng6]

The user confirmed that this is the issue: