Do not emit events from AbstractTBTCDepositor

In all cases considered so far, the child contract emits its own events in the
functions calling `_initializeDeposit` and `_finalizeDeposit`. The events
emitted by child contracts have the advantage of emitting decoded extra data in
the parameters. We could emit events from the parent contract as well but they
cost gas and we are emitting the same data in child contract events. Also, we
sometimes need to be creative in child contracts and come up with other names
than DepositInitialized and DepositFinalized even though that is exactly what
happens :)

solidity/contracts/integrator/AbstractTBTCDepositor.sol

@@ -96,14 +96,6 @@ abstract contract AbstractTBTCDepositor {
     // slither-disable-next-line unused-state
     uint256[47] private __gap;
 
-    event DepositInitialized(uint256 indexed depositKey, uint32 initializedAt);
-
-    event DepositFinalized(
-        uint256 indexed depositKey,
-        uint256 tbtcAmount,
-        uint32 finalizedAt
-    );
-
     /// @notice Initializes the contract. MUST BE CALLED from the child
     ///         contract initializer.
     // slither-disable-next-line dead-code
@@ -150,12 +142,6 @@ abstract contract AbstractTBTCDepositor {
             reveal.fundingOutputIndex
         );
 
-        emit DepositInitialized(
-            depositKey,
-            /* solhint-disable-next-line not-rely-on-time */
-            uint32(block.timestamp)
-        );
-
         // The Bridge does not allow to reveal the same deposit twice and
         // revealed deposits stay there forever. The transaction will revert
         // if the deposit has already been revealed so, there is no need to do
@@ -211,14 +197,6 @@ abstract contract AbstractTBTCDepositor {
 
         tbtcAmount = _calculateTbtcAmount(deposit.amount, deposit.treasuryFee);
 
-        // slither-disable-next-line reentrancy-events
-        emit DepositFinalized(
-            depositKey,
-            tbtcAmount,
-            /* solhint-disable-next-line not-rely-on-time */
-            uint32(block.timestamp)
-        );
-
         extraData = deposit.extraData;
     }
 

solidity/test/integrator/AbstractTBTCDepositor.test.ts

@@ -131,12 +131,6 @@ describe("AbstractTBTCDepositor", () => {
             .withArgs(fixture.expectedDepositKey)
         })
 
-        it("should emit the DepositInitialized event", async () => {
-          await expect(tx)
-            .to.emit(depositor, "DepositInitialized")
-            .withArgs(fixture.expectedDepositKey, await lastBlockTime())
-        })
-
         it("should return proper values", async () => {
           await expect(tx)
             .to.emit(depositor, "InitializeDepositReturned")
@@ -233,16 +227,6 @@ describe("AbstractTBTCDepositor", () => {
             await restoreSnapshot()
           })
 
-          it("should emit the DepositFinalized event", async () => {
-            await expect(tx)
-              .to.emit(depositor, "DepositFinalized")
-              .withArgs(
-                fixture.expectedDepositKey,
-                expectedTbtcAmount,
-                await lastBlockTime()
-              )
-          })
-
           it("should return proper values", async () => {
             await expect(tx)
               .to.emit(depositor, "FinalizeDepositReturned")
@@ -277,16 +261,6 @@ describe("AbstractTBTCDepositor", () => {
             await restoreSnapshot()
           })
 
-          it("should emit the DepositFinalized event", async () => {
-            await expect(tx)
-              .to.emit(depositor, "DepositFinalized")
-              .withArgs(
-                fixture.expectedDepositKey,
-                expectedTbtcAmount,
-                await lastBlockTime()
-              )
-          })
-
           it("should return proper values", async () => {
             await expect(tx)
               .to.emit(depositor, "FinalizeDepositReturned")