tsview --figsize-img & relaxed subset tmpl reading

[yunjunz]

Description of proposed changes

• tsview: add --figsize-img option to be able to customize the map figure size. Make this arg optional so that other existing functionalities won't be affected.

• subset.read_subset_template2box:

  • support mix separator/delimiter of : and , so that values from isce-proc also work
  • replace try/except with if judgment

Reminders

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