* tsdb/postgres: Support Unix socket for host

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Fix host regex

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Fix host regex

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Remove panic

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Fix host parsing; add tests

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Add test

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Use strings.HasPrefix to detect Unix socket host

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Remove debug logging

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Escape single quotes and backslashes

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Test generateConnectionString as requested in review

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Add test case for SSL mode

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>