fix: Hedera Transaction Builder typing improvements

[kalpana-15]

Description:
This PR documents and clarifies the correct usage of Hedera builder methods after refactoring them to remove unsafe any casts. It explains why SDK constructors should not receive unsupported parameters and how builder methods now construct transactions explicitly using SDK APIs. This helps contributors understand the design decisions and prevents reintroducing unsafe patterns in the future.

Changes included:

1. Documented why params as any was removed from builder methods
2. Clarified correct patterns for constructing Transfer, Topic, and Allowance transactions
3. Explained separation of transactionMemo and schedulingParams from SDK constructors
4. Improved readability and maintainability of builder-related code paths

Related issue(s):
Fixes the issue related to unsafe any usage in HederaBuilder transaction construction
issue #370

Notes for reviewer:
This PR does not change functionality. It documents and reinforces the refactored, type-safe builder approach already implemented.

Checklist:

• Documented
• No functional changes
• No API behavior changes

[skurzyp-blockydevs]

Hi @kalpana-15,

I’ve pushed your code to a branch in our repo and made some additional changes and fixes - your original code had a few TypeScript errors. Please see the PR: #502

Thank you for your contribution, and apologies for the delayed response!

[skurzyp-blockydevs]

Hello @kalpana-15,
we cannot merge this PR as the 5015b1c commit is not verified. You correctly signed it off but with your name and email but it was not signed with a GPG key. Please sign it and then we will merge this PR.

Also, we recommend using Conventional Commits approach for the commit messages.

[skurzyp-blockydevs]

Hi @kalpana-15 - we’d like to merge this commit. If the GPG signing issue isn’t resolved soon, we may need to squash the commit. In that case, the contribution won’t appear under your authorship, but we will make sure to credit you in the next release commit message.

[devmab]

@skurzyp-blockydevs lets just merge it