CLI to add header

[Phlya]

Since we are starting to rely on the presence of a header and column names in particular, would be nice to provide a tool to add a header to a headerless file.

[agalitsyna]

Also, because pairtools restrict and pairtools dedup can now generate additional columns, it makes some sequence of commands irreversible. E.g. files with extra columns cannot be merged with files without such columns; there is no way to add restriction sites annotation, select and then remove unnecessary fields.
Ilya and I thought of some
pairtools headerops utils that will

• add columns to the header (pairtools headerops add-header?)
• remove unnecessary fields from the whole table (pairtools headerops select?)
• check if the header complies with the content (pairtools headerops verify?)

This is not an issue but rather the discussion that might be important to decide before 1.0.0. release.

[agalitsyna]

@Phlya Can you check whether this draft is similar to what might be useful to you?
#121

Any comments or modifications are much appreciated!

[agalitsyna]

Okay, haven't heard on this suggestion for over a week, will convert it to discussion. The module is ready for testing/improvements, feel free to add ideas!