[show][techsupport][multi-ASIC] Add support to collect tech support on multi ASIC platform

[smaheshm]

• What I did
  Add support to collect tech support on multi ASIC platform

Refactored code to put together related commands in a function.

• How I did it
  Modified generate_dump script to run relevant commands on all namespaces for multi ASIC platform. On single ASIC the commands are run in default (host) namesapce.

• How to verify it

Manual verification, and pytest.

admin@svcstr-n3164-acs-1:/var/dump/sonic_dump_svcstr-n3164-acs-1_20201212_000455/dump$ ls *0
APPL_DB.json.0         broadcom.ps0                   ip.bgp.neighbor.fc00::2.rcv0    ipv6.bgp.neighbor.fc00::6.rcv0
ASIC_DB.json.0         broadcom.soc0                  ip.bgp.neighbor.fc00::6.adv0    nat.config.0
bgp.ipv6.neighbors.0   broadcom.version0              ip.bgp.neighbor.fc00::6.rcv0    nat.conntrack.0
bgp.ipv6.summary.0     COUNTERS_DB.json.0             ip.link.0                       nat.conntrackall.0
bgp.ipv6.table.0       ip.addr.0                      ip.neigh.0                      nat.conntrackallcount.0
bgp.neighbors.0        ip.bgp.neighbor.10.0.0.1.adv0  ip.route.0                      nat.conntrackcount.0
bgp.summary.0          ip.bgp.neighbor.10.0.0.1.rcv0  ip.rule.0                       nat.iptables.0
bgp.table.0            ip.bgp.neighbor.10.0.0.5.adv0  ipv6.bgp.neighbor.fc00::2.adv0  saidump0
broadcom.nat.egress0   ip.bgp.neighbor.10.0.0.5.rcv0  ipv6.bgp.neighbor.fc00::2.rcv0
broadcom.nat.ingress0  ip.bgp.neighbor.fc00::2.adv0   ipv6.bgp.neighbor.fc00::6.adv0
admin@svcstr-n3164-acs-1:/var/dump/sonic_dump_svcstr-n3164-acs-1_20201212_000455/dump$ ls *1
APPL_DB.json.1         broadcom.ps1                    ip.bgp.neighbor.fc00::a.rcv1    ipv6.bgp.neighbor.fc00::e.rcv1
ASIC_DB.json.1         broadcom.soc1                   ip.bgp.neighbor.fc00::e.adv1    nat.config.1
bgp.ipv6.neighbors.1   broadcom.version1               ip.bgp.neighbor.fc00::e.rcv1    nat.conntrack.1
bgp.ipv6.summary.1     COUNTERS_DB.json.1              ip.link.1                       nat.conntrackall.1
bgp.ipv6.table.1       ip.addr.1                       ip.neigh.1                      nat.conntrackallcount.1
bgp.neighbors.1        ip.bgp.neighbor.10.0.0.13.adv1  ip.route.1                      nat.conntrackcount.1
bgp.summary.1          ip.bgp.neighbor.10.0.0.13.rcv1  ip.rule.1                       nat.iptables.1
bgp.table.1            ip.bgp.neighbor.10.0.0.9.adv1   ipv6.bgp.neighbor.fc00::a.adv1  saidump1
broadcom.nat.egress1   ip.bgp.neighbor.10.0.0.9.rcv1   ipv6.bgp.neighbor.fc00::a.rcv1
broadcom.nat.ingress1  ip.bgp.neighbor.fc00::a.adv1    ipv6.bgp.neighbor.fc00::e.adv1

Previous command output (if the output of a command-line utility has changed)

New command output (if the output of a command-line utility has changed)