fix: cleanup star/unstar

[wraithgar]

It was querying whoami once for every package you starred/unstarred, and
incorrectly trying to determine if you weren't logged in. In fact the
function throws a descriptive message if you're not logged in already.
The whoami check was also racing with the fetch of the packument for
each package you were starring/unstarring meaning you could also get a
random 401 for a private package instead of the 'you need to log in'
message.

unstar was setting an undocumented config item to get the
shared code to unstar. The command already has a name attribute that
tells us what action we are doing so we can just use that.

Finally, the duplicated (and differing) params between the two commands
were consolidated.

[npm-robot]

no statistically significant performance changes detected

timing results

app-large	clean	lock-only	cache-only	cache-only peer-deps	modules-only	no-lock	no-cache	no-modules	no-clean	no-clean audit
npm@8	52.222 ±1.05	33.812 ±0.00	36.502 ±23.79	21.459 ±0.64	3.009 ±0.00	3.016 ±0.07	2.475 ±0.20	12.289 ±0.01	2.421 ±0.04	3.466 ±0.00
#4868	55.368 ±0.65	33.046 ±0.07	33.093 ±19.68	21.705 ±1.04	3.013 ±0.00	2.988 ±0.00	2.405 ±0.04	12.266 ±0.01	2.394 ±0.03	3.599 ±0.26

app-medium	clean	lock-only	cache-only	cache-only peer-deps	modules-only	no-lock	no-cache	no-modules	no-clean	no-clean audit
npm@8	39.894 ±0.83	25.055 ±0.06	14.454 ±0.14	14.651 ±0.24	2.771 ±0.04	2.795 ±0.05	2.434 ±0.01	8.977 ±0.16	2.274 ±0.00	3.086 ±0.02
#4868	40.108 ±0.92	25.695 ±0.16	13.727 ±0.12	14.645 ±0.28	2.763 ±0.02	2.788 ±0.02	2.489 ±0.03	8.954 ±0.07	2.263 ±0.01	3.240 ±0.14