--fee still not mandatory for build-raw in default command group

[mkoura]

Description

When invoking transaction build-raw without specifying era group, the --fee is not required. When specifying e.g. "babbage" or "conway", the --fee is required (implemented in #768).

Steps to Reproduce

cardano-cli transaction build-raw --invalid-hereafter 107199 --out-file /dev/null --tx-in "f0d9b0d157316567319d506541833627f10ec0beae68f539110ca9b8b08ad22f#0" --tx-out "addr_test1qrlauc5m5qfgpz425qjgakwuw7ttfcq7lpsyrwjg6u99hrquankfu9uqpmn8h6tsxf8xn2hx5w0ejx0nfjsfm3383z0qqvllwn+999832079"

2. See no error

cardano-cli babbage transaction build-raw --invalid-hereafter 107199 --out-file /dev/null --tx-in "f0d9b0d157316567319d506541833627f10ec0beae68f539110ca9b8b08ad22f#0" --tx-out "addr_test1qrlauc5m5qfgpz425qjgakwuw7ttfcq7lpsyrwjg6u99hrquankfu9uqpmn8h6tsxf8xn2hx5w0ejx0nfjsfm3383z0qqvllwn+999832079"

4. See Missing: --fee LOVELACE
   ...

Additional Context

cardano-cli 8.24.0.0 - linux-x86_64 - ghc-8.10
git rev ae8bc933ee6b6366c04854c1e127fd8dfb29b556

cardano-node 8.12.0 - linux-x86_64 - ghc-8.10
git rev ae8bc933ee6b6366c04854c1e127fd8dfb29b556