[ADD] base_import: batching (& some other features)

various UI changes
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* renamed "test import" button to "test"
* move relation fields thing to debug mode
* remove "Defer parent/child computation" option as it was deprecated
  / removed from the backend in
  80f1ac3599ee630e7556ff4fcf3eb192931eccd8, turns out this checkbox
  existed inactive for longer than it's been of any use (added in
  68cb2ade09206b0abb3f7c8dccb5d35a6499f802 on 2017-11-29, made
  non-operating on 2018-01-24, that's so sad)

batching
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* add support for batching imports (skip & limit parameters)
* modify client to use batched imports & properly adapt responses so
  it still looks like a single import for the client (more or less)
  e.g. update row numbers in error messages, etc...
* properly handle partial imports though
* disable usual loading throbber to have a single progress
  notification displayed continuously throughout all the batches: the
  normal throbber only shows after 3s of waiting for an RPC response,
  so it would keep flashing in and out (appear 3s into a batch's
  import then disappear at the end only to reappear 3s into the next
  batch's loading)

NOTE: the limit is row-wise. If a record straddles the limit (because
of nested O2M records), the record is imported in full and the "next
row" is whatever row follows the record. This means a limit of 10 can
lead to an import of 17 lines, and as the progress indicator is in
records# the increments can jump around.

Task 2059448

0 files changed, 0 insertions, 0 deletions