oracledb thin client - support locale specific date and number conversion

Currently there is no native support for the python oracledb module, so this issue occurs when using "connect using custom params" mode (see #173 for connection example).
There is a problem if the test data used in Robot Framework has some regional format different from the Oracle DB.
For example, with decimal/float number and dates:

• The standard English Oracle format for a decimal number is point-based - e.g. 123.45.
• But in some other languages/regions (e.g. in Germany) the comma-based format is used - 123,45.

So before I save some local values to the database or compare them with the database values, there is some conversion to be done.
Currently it has to performed manually.

Maybe there is a better way?

The thin mode of the oracledb client doesn't support Oracle Globalization variables (see the full comparison between thin and thick clients here).
So they advice to use the python globalization support - and provide an example.

Also I'm not sure, but maybe this issue is relevant also for other databases?

先從 issue #173 中的 custom-params 連線模式和連線範例開始，然後閱讀連結的 python-oracledb thin-mode 全球化範例。定義 Robot Framework 測試資料應如何進行支援 locale 的日期和數字轉換，並明確範圍是否包括 Oracle 以外的資料庫。