Resolve "Tabular parser - using column and row modes together only works for children repeated sections"

The top most section that inherits from TableData enforces that all the subsequent subsections should retain the same mode of operation as the top most section. For example, when top most section is annotated with column mode, then all sub-sections should be annotated with column mode as well. This causes some limitations when implementing a mixed mode in an ELN YAML/JSON file.

Closes #1354 (closed)