feat(playground): add memory catalog support

[Shekharrajak]

Which issue does this PR close?

• Closes Support memory catalog in playground #1160

What changes are included in this PR?

• Added MemoryCatalogBuilder
• Changed the return to use the already-Arc-wrapped catalog
• Replaced the hardcoded rest-only check with a match statement: Easy extensibility (just add a new match arm for new catalog types)

Are these changes tested?

After build :

$ cargo build -p iceberg-playground --release 

$ cat ~/.icebergrc 
[[catalogs]]
name = "local"
type = "memory"
[catalogs.config]
warehouse = "/tmp/iceberg-warehouse"



$ ./target/release/iceberg-playground --rc /path/to/config.toml