[Bug] Convert timestamp_ltz field contents using local time zone

### Search before asking

- [X] I searched in the [issues](https://github.com/apache/paimon/issues) and found nothing similar.

### Paimon version

0.8

### Compute Engine

flink

### Minimal reproduce step

1. Create a mysql table containing the timestamp type, and specify the time zone for mysql server to be UTC+8
2. Use flink-cdc to import the data of the table into kafka
3. Create a paimon table, which uses a timestamp_ltz type field to store the value of the timestamp type field in mysql
4. If you query the paimon table in UTC+8, you will find that there are still 8 hours missing

### What doesn't meet your expectations?

The content of the timestamp_ltz field retrieved from the Paimon table should be the same as in mysql

### Anything else?

I think the root cause is that we use the utc time zone to read the data from kafka, but use the current time zone to write the data to paimon.


### Are you willing to submit a PR?

- [X] I'm willing to submit a PR!

Start with the minimal reproduction involving MySQL, Flink CDC, Kafka, and a Paimon timestamp_ltz field, comparing results under UTC+8. Trace whether Kafka data is read in UTC and written to Paimon in the current time zone; done means querying the Paimon table returns the same timestamp as MySQL.

Written by the indexing model from the issue text.