Remove unused `TransactionEncoder` functions #1549

Job	Run time
validate_gradle_wrapper	6s
check_firebase_secrets	1s
check_emulator_wtf_secrets	1s
check_properties	3m 20s
static_analysis_ktlint	3m 57s
demo_app_release_build	24m 2s
static_analysis_android_lint	19m 47s
static_analysis_detekt	3m 35s
test_android_modules_ftl	0s
test_android_modules_unit	20m 35s
test_android_modules_wtf	20m 31s
test_robo_demo_app	3m 58s
	1h 39m 53s

Provide feedback