chore: adjust documentation

[naydenovn]

Description:
Adjusting java documentation where necessary. Documentation is inspired by protobufs and tests

Related issue(s):

Fixes #
#2120
Notes for reviewer:

Checklist

• Documented (Code comments, README, etc.)
• Tested (unit, integration, etc.)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.69%. Comparing base (b86ee46) to head (9aac194).
Report is 225 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2181      +/-   ##
============================================
- Coverage     82.20%   78.69%   -3.51%     
- Complexity     3588     4094     +506     
============================================
  Files           186      243      +57     
  Lines         11697    13740    +2043     
  Branches       1150     1335     +185     
============================================
+ Hits           9615    10813    +1198     
- Misses         1604     2454     +850     
+ Partials        478      473       -5     

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Files with missing lines	Coverage Δ	Complexity Δ
...hgraph/sdk/AccountAllowanceApproveTransaction.java	84.92% <ø> (ø)	36.00 <0.00> (?)
...shgraph/sdk/AccountAllowanceDeleteTransaction.java	79.68% <ø> (ø)	14.00 <0.00> (?)
...hedera/hashgraph/sdk/AccountCreateTransaction.java	93.79% <ø> (ø)	43.00 <0.00> (?)
...hedera/hashgraph/sdk/AccountDeleteTransaction.java	78.04% <ø> (ø)	11.00 <0.00> (?)
...hedera/hashgraph/sdk/AccountUpdateTransaction.java	68.87% <ø> (ø)	35.00 <0.00> (?)
...edera/hashgraph/sdk/ContractCreateTransaction.java	85.25% <ø> (ø)	43.00 <0.00> (?)
...edera/hashgraph/sdk/ContractDeleteTransaction.java	73.58% <ø> (ø)	13.00 <0.00> (?)
...dera/hashgraph/sdk/ContractExecuteTransaction.java	83.63% <ø> (ø)	13.00 <0.00> (?)
...edera/hashgraph/sdk/ContractUpdateTransaction.java	67.51% <ø> (ø)	35.00 <0.00> (?)
.../com/hedera/hashgraph/sdk/EthereumTransaction.java	77.27% <ø> (ø)	9.00 <0.00> (?)
... and 36 more

[0xivanov]

LGTM