fix: do not send continue events (xdebug#307)

A debug adapter is not expected to send this event in response to a request that implies that execution continues, e.g. 'launch' or 'continue'.
It is only necessary to send a 'continued' event if there was no previous request that implied this.

Note: there is still the problem that it will seem to "hang" when you continue and the PHP code takes a while to run, xdebug#308 will fix that.

Fixes xdebug#301

src/phpDebug.ts

@@ -279,10 +279,6 @@ class PhpDebugSession extends vscode.DebugSession {
                         })
                         connection.on('error', disposeConnection)
                         connection.on('close', disposeConnection)
-                        connection.on('before-execute-command', () => {
-                            // It is about to start executing PHP code
-                            this.sendEvent(new vscode.ContinuedEvent(connection.id))
-                        })
                         await connection.waitForInitPacket()
 
                         // override features from launch.json

src/xdebugConnection.ts

@@ -679,11 +679,6 @@ export class Connection extends DbgpConnection {
         const data = iconv.encode(commandString, ENCODING)
         this._pendingCommands.set(transactionId, command)
         this._pendingExecuteCommand = command.isExecuteCommand
-        if (this._pendingExecuteCommand) {
-            // Since PHP execution commands block anything on the connection until it is
-            // done executing, emit that the connection is about to go into such a locked state
-            this.emit('before-execute-command')
-        }
         await this.write(data)
     }