Fix ER_OUTOFMEMORY format to use %zu and size_t (MDEV-39138)

[Harsh8084]

Updated the error message format and all related call sites to use %zu (size_t format) and size_t arguments, ensuring proper handling of large memory values without overflow risk.

Changes Made
Error Message Format

Changed ER_OUTOFMEMORY format from %d to %zu across all language variants.
Fixed a malformed Georgian translation line (missing closing quote).

Source Code Updates
Removed (int) casts and ensured size_t arguments in my_error(ER_OUTOFMEMORY, ...) calls.
Files: handler.cc, item_jsonfunc.cc, item_strfunc.cc, session_tracker.cc, set_var.cc.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
10 out of 13 committers have signed the CLA.

✅ DaveGosselin-MariaDB
✅ bnestere
✅ MohamedM216
✅ ChandanaRamakrishna
✅ varundeepsaini
✅ Harsh8084
✅ kevdn
✅ svoj
✅ tonychen2001
✅ ParadoxV5
❌ vuvova
❌ abarkov
❌ montywi
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[gkodinov]

How is this one different from #4850? Please close the one you do not need.

And please, going forward, do not keep more than 1 PR open per MDEV! It makes is much harder for me to process these.