Remove per chart configuration. (#12728)

After https://github.com/netdata/netdata/pull/12209 per-chart configuration
was used for (a) enabling/disabling a chart, and (b) renaming dimensions.

Regarding the first use case: We already have component-specific
configuration options|flags to finely control how a chart should behave.
Eg. "send charts matching" in streaming, "charts to skip from training"
in ML, etc. If we really need the concept of a disabled chart, we can
add a host-level simple pattern to match these charts.

Regarding the second use case: It's not obvious why we'd need to provide
support for remapping dimension names through a chart-specific configuration
from the core agent. If the need arises, we could add such support at
the right place, ie. a exporter/streaming config section.

This will allow each flag to act indepentendly from each other and
avoid managing flag-state manually at various places, eg:

```
    if(unlikely(!rrdset_flag_check(st, RRDSET_FLAG_ENABLED))) {
        rrdset_flag_clear(st, RRDSET_FLAG_UPSTREAM_SEND);
        rrdset_flag_set(st, RRDSET_FLAG_UPSTREAM_IGNORE);
    } ...
```

1 files changed, 0 insertions, 1 deletions

diff --git a/exporting/tests/exporting_fixtures.c b/exporting/tests/exporting_fixtures.c
index b632761e7e..501fc405c9 100644
--- a/exporting/tests/exporting_fixtures.c
+++ b/exporting/tests/exporting_fixtures.c
@@ -58,7 +58,6 @@ int setup_rrdhost()
     st->rrdhost = localhost;
     strcpy(st->id, "chart_id");
     st->name = strdupz("chart_name");
-    st->flags |= RRDSET_FLAG_ENABLED;
     st->rrd_memory_mode |= RRD_MEMORY_MODE_SAVE;
     st->update_every = 1;