util/num2float: handle a few int cases typically seen on windows

build: fix broken installations by using the freshest pip

Also we also include tsview in the repos to be tested.

api/group_rename: full api support for group renaming

tsio/group: add the ability to rename a group

test/api: complete group validation checks after more stringent checks have been introduced

NOTE: these tests should move to tshistory_formula.

tsio/update_group_metadata: add support for "internal"

While doing so we simplify a bit the group metadata handling.
This will help tsview get all group metadata in one big efficient query.

group/metadata: make sure we yield None for a non-existent group

build: pin a pandas version

Pip becomes crazy if we do not help him a bit.

group/metadata: really exhibit the internal metadata

We pick a random series member to have it.

group/sql: better wording

group/metadata: accept the "all" parameter

This allows filtering vs the internal metadata. Needed for the views at least.

http/server: implement the json format for group_get

This will be necessary for at least the web ui in tsview.

test/http: group series and groups tests together for clarity

pkg: make sure we run a recent enough flask-restx

We unleashed modern flask versions, this comes with the territory.

pkg: switch to a more recent flask

tsio/make_tablename: fix the collision detection path

We never wrote a test for this, and hence it was broken.

test/rename: exhibit failure to reuse a series with a long name after a rename

util/unflatten: fix unflattening when we have keys with many dots

test/util/unflatten: show that we are quite weak at this job

util/fromjson: return an empty series with a datetime index when needed

We were missing an use of `empty_series` there.