This API is a benefit when the caller is only interested in parsing
tags and reusing an existing Tags buffer. It will be used by the
storage schema APIs.
We will want to validate that all tag key/value data is valid unicode.
This commit changes the validation helper to only validate provided
tags, since measurements are currently very likely to contain invalid
utf-8 characters.
There are two exceptions to the tag validation: the validation of the
special tag keys for measurements and field keys.
I did this with a dumb editor macro, so some comments changed too.
Also rename root package from platform to influxdb.
In interest of minimizing risk, anyone importing the root package has
now aliased it to "platform" so that no changes beyond imports were
necessary in those files.
Lastly, replace the old platform module to local path /dev/null so that
nobody can accidentally reintroduce a platform dependency while
migrating platform code to influxdb.
Type conflicts should be rare, but when they do happen, printing out the
string name should save developers a couple minutes of digging compared
to looking up which numeric value means which type.