Fix `test_tf_encode_plus_sent_to_model` for `TAPAS`
# What does this PR do?

`TapasTokenizer.encode_plus` requires a `table` argument. Currently, this test calls `TokenizerTesterMixin.test_tf_encode_plus_sent_to_model`, therefore it didn't provide this argument and fails.

This PR completely overwrites this test in `TapasTokenizationTest`, just like the pytorch one `test_torch_encode_plus_sent_to_model`.
_The documentation is not available anymore as the PR was closed or merged._