feat: expose new methods on txbuilder

bdk-android/lib/src/androidTest/kotlin/org/bitcoindevkit/LiveWalletTest.kt

@@ -15,6 +15,8 @@ class LiveWalletTest {
         val update = esploraClient.scan(wallet, 10uL, 1uL)
         wallet.applyUpdate(update)
         println("Balance: ${wallet.getBalance().total()}")
+        val balance: Balance = wallet.getBalance()
+        println("Balance: $balance")
 
         assert(wallet.getBalance().total() > 0uL)
     }

bdk-android/lib/src/androidTest/kotlin/org/bitcoindevkit/OfflineDescriptorTest.kt

@@ -1,6 +1,7 @@
 package org.bitcoindevkit
 
 import kotlin.test.Test
+import kotlin.test.assertEquals
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import org.junit.runner.RunWith
 import kotlin.test.assertEquals