Update 2025-12 - ImportHelper Script for ConwayEra

Updates:

• The 0x_importHelper.sh script was updated to be compatible with latest cardano-cli release 10.12.0.0.
• The script was lacking the requirements to set the correct stakeaddress-deposit-fee value in conway era while generating the xxx.deleg.cert file during the import process.
• Also some minor changes in the calling commands for cardano-cli.

Other changes:

• Minimum cardano-hw-cli version is now set to 1.19.0 to be in line with the new trezor message signing functions.