additions to the statistics page

[bansp]

As opposed to the discussion ticket #202 , this is a task description.

https://standards.clarin.eu/sis/views/list-statistics.xq

Suggestions:

1. split the page into "Format statistics" and "Centre statistics"
2. under Format statistics, in the existing tables for Domains and Media types, make it possible to sort alphabetically in column 1 and numerically in column 2
3. under Centre statistics, add:
   1. table, with 4 columns: first: "RI", second: number of centres, third: number of depositing centres, fourth: number of curated centres;; and with 4 rows: all, CLARIN, Text+, DARIAH (these should preferably be dynamic, but we can leave the dynamicity for the future)
   2. I'll take care of the headings, a note warning that all < CLARIN + T+ + DARIAH, etc.

[bansp]

Adding priority as agreed at the meeting