Find alternative default variants for taps/targets where `meltano` variant is currently the default

A number of the extractors and loaders on https://hub.meltano.com/extractors/ and https://hub.meltano.com/loaders/ have the meltano variant from https://gitlab.com/meltano/ or https://github.com/meltano/ as the default (https://hub.meltano.com/singer/maintainers/meltano), but we don't want to continue maintaining these if we don't have to. Let's find actively maintained alternative variants/forks and drive people to these instead. In a few cases that may actually be the singer-io variant.

Extractors:

• tap-csv meltano#2963 (closed)
• tap-facebook (ads) meltano#2964 (closed)
• tap-gitlab meltano#2965 (closed)
• tap-adwords meltano#2966 (closed)
• tap-google-analytics meltano#2967 (closed)
• tap-marketo meltano#2968 (closed)
• tap-salesforce meltano#2969 (closed)
• tap-stripe meltano#2970 (closed)
• tap-fastly meltano#3060 (closed)

Loaders:

• target-sqlite meltano#2971 (closed)