tests: bluetooth: mesh: Add PB-GATT provisioning test cases

Extending existing provisioning test code to use PB-GATT and adding
test cases for provisioning over PB-GATT. Test names are changed to
represent both provisioning brearers. Enabled required kconfigs for
PB-GATT and GATT proxy features in overlay_gatt.conf. Test argument
prov-bearer is added to provisioning tests to select bearer.

Following tests are renamed and extended to use PB-GATT
- pb_adv_multi
- pb_adv_no_oob
- pb_adv_oob_auth_ib_pk
- pb_adv_oob_auth_ignore_oob_pk
- pb_adv_oob_auth_oob_pk
- pb_adv_reprovision

PB-GATT test cases will run only with PSA encryption since tinycrypt
is to be deprecated.

Signed-off-by: alperen sener <alperen.sener@nordicsemi.no>