Bylaw changes for 2023 X.org vote

Note that this branch contains two independent bylaw change proposals, which are voted on independently:

• Adopt SFC as new fiscal sponsor for X.org, which is the majority of the changes
• Change the special voting quorum requirements to be limited to present (meaning voting) members from the current rule of all members. This is 564b7711

For best reviewing of the changes in the gitlab UI uncheck the box to show whitespace changes. Also note that gitlab highlights the specific words that have been changed, which makes reviewing the replacement commits much easier.