Store more info about filter (in tree comment)

[westram]

Motivation:

• the filter applied to the sequence data used for reconstruction generally has a strong impact on result.
• when comparing different results (trees) esp. the filter information should be directly accessible (e.g. allow to sort trees by filter-information; needs #758)

Information to store in comments:

1. name of program
2. name of used filter
3. store number of resulting (i.e. effectively used) alignment columns (in exported or used sequence data), e.g. as additional tag FCOLS=<num> behind FILTER=<name>

Notes:

• 1.+2. definitely missing for parsimony
• check whether 1.+2. work properly for other treeing tools (esp. raxml8 which was implemented with a custom script after the last global change of -comment-format)

---

requires: #758