Add rune transaction creation method

[Maximkaaa]

Motivation

Add methods to create and sign rune edict transactions.

Closes EPROD-813 (https://infinityswap.atlassian.net/browse/EPROD-813)

Changes

Test Plan

TODO

• Explain motivation or link existing issue(s)
• Test changes and document test plan
• Update documentation as needed

DevOps Notes

• This PR does not require configuration changes (e.g., environment variables, GitHub secrets, VM resources)
• This PR does not affect public APIs
• This PR does not rely on a new version of external services
• This PR does not make changes to log messages (which monitoring infrastructure may rely on)

By submitting this pull request, I confirm that my contribution is made under the terms of the MIT license.

[veeso]

Can we have a unit test as it's been done for brc20 just to check if the inscription flow works?

[Maximkaaa]

Hey, @veeso , I've added the test for runes. The only issue there is that the fee estimation seems to work incorrectly (although, not by much). Since this is somewhat unrelated issue to the runes edict transaction creation, and is not critical for actual usage of the code in bridge canister (since it will not use taproot inputs for now), I created a separate ticket for this: https://infinityswap.atlassian.net/browse/EPROD-830 .