Simplify getBytes and getSigningBytes

[bobanm]

What was the problem?

This PR resolves #9061

How was it solved?

• Extracted common functionality to encodeParams() function
• Reverted the conditional for checking if params are valid
• Updated validateTransaction() to throws error instead of returning an error
• Updated encodeParams() to default params schema to emptySchema

How was it tested?

All existing tests have passed 👌🏻

[codecov]

Codecov Report

Merging #9062 (5cf34e9) into development (773ba74) will decrease coverage by 0.90%.
Report is 2 commits behind head on development.
The diff coverage is 92.85%.

❗ Current head 5cf34e9 differs from pull request most recent head 7608396. Consider uploading reports for the commit 7608396 to get more accurate results

@@               Coverage Diff               @@
##           development    #9062      +/-   ##
===============================================
- Coverage        84.35%   83.46%   -0.90%     
===============================================
  Files              655      604      -51     
  Lines            24137    22776    -1361     
  Branches          3506     3356     -150     
===============================================
- Hits             20361    19010    -1351     
+ Misses            3776     3766      -10     

Files	Coverage Δ
elements/lisk-transactions/src/validate.ts	100.00% <100.00%> (ø)
elements/lisk-transactions/src/sign.ts	98.07% <94.44%> (-1.93%)	⬇️
framework/src/testing/create_transaction.ts	20.83% <0.00%> (+1.60%)	⬆️

... and 103 files with indirect coverage changes