Need a tool to show database space usage

[punktilious]

Is your feature request related to a problem? Please describe.
In order to understand database space growth, need a tool to query and display usage distribution. How much space is used across the resources, search parameters, indexes etc.

Describe the solution you'd like
An extension to the fhir-persistence-schema CLI tool.

Describe alternatives you've considered
Manually query the database each time the information is required, but this is not desirable in a production environment. Also, the queries to collect this data will be very different for PostgreSQL and Db2, so it would be useful to hide this complexity in a tool.

Acceptance Criteria

1. GIVEN a PostgreSQL with the FHIR schema deployed
   WHEN the schema-tool is run using the --show-db-size option
   THEN a summary report is written to stdout.

2. GIVEN a PostgreSQL with the FHIR schema
   WHEN the schema-tool is run using the --show-db-size option
   AND the --show-db-size-detail option is included
   THEN both summary and detailed reports are written to stdout

3. GIVEN a Db2 with the FHIR schema deployed
   WHEN the schema-tool is run using the --show-db-size option
   AND a schema name is provided
   AND a tenant name is provided
   THEN a summary report is written to stdout.

4. GIVEN a Db2 with the FHIR schema
   WHEN the schema-tool is run using the --show-db-size option
   AND a schema name is provided
   AND a tenant name is provided
   AND the --show-db-size-detail option is included
   THEN both summary and detailed reports are written to stdout

Additional context
Possibly also include machine-readable output so that the tool can be used to provide metrics to a performance management solution. (*) now supported using the --show-db-size-detail option.

[kmbarton423]

Confirmed expected behavior with both postgres and db2:

java -jar ./fhir-persistence-schema-4.11.0-SNAPSHOT-cli.jar --prop-file C:\KMBspace\aFHIR\docker\postgresql.properties --schema-name fhirdata --db-type postgresql --show-db-size
java -jar ./fhir-persistence-schema-4.11.0-SNAPSHOT-cli.jar --prop-file C:\KMBspace\aFHIR\docker\postgresql.properties --schema-name fhirdata --db-type postgresql --show-db-size --show-db-size-detail

java -jar ./fhir-persistence-schema-4.11.0-SNAPSHOT-cli.jar --prop-file C:\KMBspace\aFHIR\docker\db2.properties --tenant-name default --schema-name FHIRDATA --db-type db2 --show-db-size
java -jar ./fhir-persistence-schema-4.11.0-SNAPSHOT-cli.jar --prop-file C:\KMBspace\aFHIR\docker\db2.properties --tenant-name default --schema-name FHIRDATA --db-type db2 --show-db-size --show-db-size-detail