Create additional table for `extra_info_descriptor` bandwidth histories

The {read, write}-history columns in the extra_info_descriptor table contain JSON, what it's already can be queried with PostgreSQL.

Example read_history row:

{"line":
  "read-history 2023-06-17 21:04:08 (86400 s) 6024585216,3048128512,4642625536,2614033408,2343061504",
  "historyEndMillis":1687035848000,
  "intervalLength":86400,
  "bandwidthValues":{"1686690248000":6024585216,"1686776648000":3048128512,"1686863048000":4642625536,"1686949448000":2614033408,"1687035848000":2343061504}
}

For some queries, like the ones we're working on at tpo/network-health/team#313, it's still a bit complex to create queries with JSON and i ended up creating my own local DB with a table just for the bandwidth values. This is why i've thought that maybe it's helpful for other projects too to have this additional table.

It could also be in a different database or be created outside of this project code, from the existing tables (instead of the descriptors) or in a different programming language.

For tpo/network-health/team#313 the scheme i created from the read/write-history bandwidthValues is:

CREATE TABLE public.bw_history (
    fingerprint character varying(40) NOT NULL,
    ts timestamp without time zone NOT NULL,
    read_bytes bigint NOT NULL,
    write_bytes bigint
);
ALTER TABLE ONLY public.bw_history
    ADD CONSTRAINT bw_history_pkey PRIMARY KEY (fingerprint, ts, read_bytes)

Example row:

               fingerprint                |         ts          | read_bytes | write_bytes
------------------------------------------+---------------------+------------+-------------
 9AB08DD5D3F20BA7DDC693061B65DAF4E6B1F901 | 2023-09-15 16:02:10 |  270259200 |   259977216

but maybe other projects need historyEndMillis or intervalLength fields too.

This issue might be related to #34

Update: there're already bandwidth histories in the Victoria Metrics database (https://metrics-db.torproject.org). The question now would be how to filter bandwidth histories by fingerprints obtained from the PostgreSQL database (metricsdb-01.torproject.org)