Remove `ExportTableToFileOperator` in 1.5.0 release

[pankajastro]

• Wanted to rename ExportFileOperator
• Deprecated ExportFileOperator added ExportTableToFileOperator and released it inastro-sdk-python-1.3.1`
• Later we come to the conclusion that ExportToFileOperator is a better name choice for this.
• Deprecated ExportTableToFileOperator and added ExportToFileOperator in astro-sdk-python-1.4.0.

Next action: We should consider removing ExportTableToFileOperator in astro-sdk-python-1.5.0 if possible

1.4.0 changelog: https://astro-sdk-python.readthedocs.io/en/stable/CHANGELOG.html#id1 1.3.1 changelog: https://astro-sdk-python.readthedocs.io/en/stable/CHANGELOG.html#id8